I don't have a Spines/Willpower, but I have a Spines/Dark in the 40s. My endurance consumption has been manageable with SOs and frankenslotted attacks, and I only keep a single column of blues in my inspiration tray.
As for survivability, meh. On the other hand, I took Spines/Dark to be the opposite of what I normally play unkillable single-target monsters. Maybe the survivability is fine in comparison to more normal characters. It's not like I die a lot, but I generally hunt larger and lower level crowds than I do on my other characters. That's probably where the XP sweet spot is anyway, so it's not like I'm suffering. I'm just used to better.
Also, any survivability issues may be a problem with the guy behind the keyboard. It's a different enough combination from my normal play that you're doing it wrong! is a reasonable explanation for any problems.
Oh, and I got creamed through the teens. But that's often the case with scrappers. It got a lot better in the twenties.
"That's because Werner can't do maths." - BunnyAnomaly
"Four hours in, and I was no longer making mistakes, no longer detoggling. I was a machine." - Werner
Videos of Other Stupid Scrapper Tricks
I find my spine/dark drawing a lot of agro, I have not maxed the resistance out of her yet. She is one of the toons I like to play alot. The Dark self heal is great, but if I forget about it or wait to long I am using the rez (stuns long enought to get all powers re-clicked).
Lead Squirrel at Dr. E Spider robotic site #643
Nothing saids its your spot like an ourob. Portal dropped on the ground.
Okay, I have a lvl50 Spines/Dark and the reality is, they're End Hogs, but they're also fantastic damage machines, and be made to be just as survivable as any WP scrapper
(Give Oppressive Gloom some +Acc love and its amazing, I previously dissed it in the past but OMG)
It's not an expensive build, but does have the miracle, numina & Performance shifter along with a few set bonuses for +End, along with Conserve Power.
He needs them.
In mids, it shows me as 2.2End usage a sec, and 3.3 Recovery p/sec,
The reality in general play though is it isn't that bad, most of the powers (Throw spines and spines burst) have long cast times anyway, and are usually enough to flatten 90% of a mob, after that you spend so much time running after stragglers or to the next mob, that your blue bar has plenty of recovery time.
And like i said, Dark can be hugely survivable, my guess, considering how quickly it chews mobs up, probably better than WP (as you'll forever run out of RttC bait)
I can post the build if you want,
But yeah, if you're leaning towards Spines /Dark, do it.
Oprrecsive Gloom and Cloak of Fear should be second nature to you, and you can rip through minions quicker than fire/kins.
don't worry about the End, but pack blues, and don't worry about survivability, you'll have a ton.
End use isnt really all that bad once you have everything slotted and a few good IO's under your belt. My spines/dark never had much of a problem during normal gameplay, and this was before the introduction of purples.
And, surviveable? Throw some defense sets into the mix and you can out-survive some tankers 
You definitely won't be soloing AV's though.. heh... For starters, spines shines in AoE but is very lackluster in single target damage.
On Survivability.
There is no such thing as a bad Scrapper Secondary.
I've played every secondary to at least the mid 30s and i've done most of that without using mids, and by mostly guessing as I went along.
And I made mistakes. A lot of them. So I've managed to end up with some pretty gimped scrappers, it had nothing to do with the sets themselves, but more about how I'd slotted them, point is -
All scrapper secondaries can be very weak
But, the game has respecs available, and generally, after trying a set "Raw" and learning those lessons the hard way, I'll open up Mids, or look around here on the forums at other builds and respec my poor scrapper, and more often than not put the focus on survivability and what i'v found is -
All scrapper secondaries can outperform Tanks.
I can't count the number of times my scrappers have saved stoopid tanks, And Dark Armor is no exception.
So Dark Survivability numbers - -
* With tough added, he has over 50% Smash/lethal res.
* With a few IO bonuses he has over 30% positional defenses.
* Dark Regeneration is the games single most powerful heal.
* And it has mez auras in the form of CoF & OG,
Which is an awful lot of suvivability, tons of it.
So yeah, the survivability the set offers sghould never be the issue, it's more abpout what else it offers, to put it in simple terms,
DA has Death shroud for extra damage. It will also be more expensive to 'trick' out (but it's worth it)
WP has Quick recovery and need never, ever worry about blue, and is actually LESS survivable at lower levels (though pulls ahead in the late game)
hope that helps
BUT can you farm with it?
you can farm normal mobs with ease, the AE boss farms will be more challenging but it can be done, just not as carefree.
Spines/ D A lvl 50 Scrap, stone/wm lvl 50 tank, Kat/reg lvl 50 Scrap
Grav/Kin lvl 50 Cont, Fire/Enegry lvl 50 Blast
Warshade lvl 50, PB lvl 39, nightwidow lvl 50, crab lvl 42
plant/thorns lvl 50 dom, ice/fire lvl 40 dom, grav/nrg lvl 41 dom
But But But I want my SUper Duper Dev powers to instantly smite all enemies and be able to farm all maps instantly and uberly
Spines/Dark is a blast to play but it blooms late and costs a pretty penny to get all the IO help it needs, not really an issue if you have a 50 or play the market at all. It takes some discipline to level it up.
It cannot be stressed enough spines plays very differently than all the other scrapper secondaries, you are an aoe monster with adequate but subpar single target damage. Dark perhaps more than any other scrapper secondary feeds into this and makes you a minion killer.
I would also argue on teams /dark gains more from team buffs than any other secondary. You have a wide ranging blanket of protection in resistance/defense/mez/heals so any buff tends to benefit you more than most. On teams with almost any kind of buffage you will kill spawns so fast the blasters and tanks will feel useless.
Specifically with a kinetic speed boosting you, your a god, it solves your endurance issues and speeds up Dark Regen letting you tank for teams, but this takes timing and playing right on the edge of life or death. Which makes it really fun.
I have a fully IO'd Spines / WP Scrapper...and I love her!
Entirely amazing and a breath to behold in action. Plus...I never run out of endurance! Now, if only my Spines / Fire Scrapper could say the same thing...
[ QUOTE ]
I have a fully IO'd Spines / WP Scrapper...and I love her!
Entirely amazing and a breath to behold in action. Plus...I never run out of endurance! Now, if only my Spines / Fire Scrapper could say the same thing...
[/ QUOTE ]
I'm actually real happy you posted this. I have a Spines/WP scrapper that's only level 24. I've been pondering whether to continue with him or not - especially considering all the projects I have going - and the fact that I don't yet have a level 50 (hit 43 on my DM/WP scrap tonight - woot).
So, it's great to hear that someone really enjoys the combo. Seems solid enough for me, i just wondered if I should have coupled spines with dark or fire sometimes. Course, I can always try that too sometime.
Acidon
I enjoyed my Spines/Dark up through level 43, but I wasn't playing a normal build. Some cruel person made a hilarious "Toggleman" post that inspired me to build a character with nearly all toggles. One of these days I should try to finish getting him to 50 just so I can say I did it.
I'd probably have an easier time of it if I made an alternate build for the character, but that would defeat the purpose! 
Goodbye may seem forever
Farewell is like the end
But in my heart's the memory
And there you'll always be
-- The Fox and the Hound
Get the Theft of Essence Proc in Dark Regen and that should help as well.
Probably an odd question for you scrapper forum folks, as they would seem to function differently. I'm looking for some advice on a new character concept and both options would work for the ideas I have in mind. I'm mostly a defender/controller player but recently got both a scrapper and tanker to 50 and am looking for some more melee fun. I am leaning toward the Spines/dark if I can make it work as my 50 scrapper is a claws/WP and would like to try some new sets. I'm concerned about a few things with dark, pardon my noobness if these are silly issues:
1. End consumption: I'm not afraid to spend the inf on expensive builds to make it work but even in mids I can't seem to find a way to make a build that doesn't kill my blue bar. I am taking tough/weave/combat jumping when planning in mids, partly for my second reason listed here, but my end consumption is almost always over 2/eps with all the toggles running.
2. Survivability: I'm not looking to solo AV's (although I do love a challenge) but how does dark fair? With my tanker I just finished an IO build (shield/SS) and feel pretty unstoppable when I play him. Similarly on my claws/WP I don't fear wading into the thick of large mobs. Some friends and I often run TFs full speed ahead, tearing through large mobs. I'd like to keep pace with the WP/SS tanker he is running if I can.
So for those of you with experience on these two builds, please let me know your thoughts. If possible, I'd love some build suggestions for spines/dark. (I feel pretty good about what I am coming up with for Spines/WP). Thanks much folks!