Squishy? you haven't met my regen(s) have you? 
*chuckles* Squishy Regens? That's a good one, will have to remember that
"Well, they found my diary today.
They were appropriately appalled
at the discovery of the eight victims
They're now putting it all together.
Women wrapped in silk
with one leg missing
Eight legs, one body, silk,
spider, brilliant!"
Invulnerability is better at taking the alpha strike from a group. Regen is better at everything else (although Unstoppable from Invulnerability does allow for some stretches of very high performance from an Inv scrapper 
).
Defiant 50�s: Generalissimo, Righteous Bob, Splortch, Brutus Cayuga
Union 50's: Chimera Obscura, Diet Anthracite, Grim Proctologist, Puny Little Minion, Raging Bitumen
In Soviet Russia, mission farm you!
regen is great with integration, the 2 self heals and of course Instant healing.
I find before taking on a boss or any purple bad guy banging on IH and conserve power lets me take them on no problem.
regen owns all
Since I5 hit and Instant Healing was no longer a toggle, I've always thought of regens as squishy so I relate. They are squishy in a if I make a mistake you can't kill me way. They are far more forgiving than a real squishy though.
That's why Unthing is a scraster.
@Unthing ... Mostly on Union.
Regens arent squishy, they just dont have sheilds like other sets but the self heals makes up for it.
IH may no longer be a toggle but its still a gr8 power and wat is a scraster????
From personal experience I'd take inv
Lately I've mostly been tanking AVs and stuff for my friendson my kat/inv scrapper and havent had any big problems doing it. I've tried regen but it didnt really suit me, smashing self heals and that stuff is damn annoying if you got even a bit of lag. There are 2 sides of the coin though, best thing about regens is 0 downtime but worst thing is that they can die in 1 hit :/
Best thing about inv is that you withstand alot of hits, even from an AV/EB but the worst thing is (doesnt go for me but many say) the end cost
- @DSorrow - alts on Union and Freedom mostly -
Currently playing as Castigation on Freedom
My Katana/Inv Guide
Anyone who doesn't take truth seriously in small matters cannot be trusted in large ones either. -Einstein
make both mate, see what one you like the best
Scraster = scrapper/blaster
how can you have a scrapper/blaster lol
What powers can you have to be able to blast except a couple of spine attacks?
Isnt a blaster's damage output higher than a scrappers?
Impale
Throw Spines
Shurikens
Exploding Shurikens
If I ever cure myself of altitis and actually finish levelling my spines scrapper (sitting at 42 at the moment) that's the kind of ranged attack build he's going with.
Defiant 50�s: Generalissimo, Righteous Bob, Splortch, Brutus Cayuga
Union 50's: Chimera Obscura, Diet Anthracite, Grim Proctologist, Puny Little Minion, Raging Bitumen
In Soviet Russia, mission farm you!
[ QUOTE ]
Impale
Throw Spines
Shurikens
Exploding Shurikens
If I ever cure myself of altitis and actually finish levelling my spines scrapper (sitting at 42 at the moment) that's the kind of ranged attack build he's going with.
[/ QUOTE ]
On comparison my PVP blaster has a grand total of 1 ranged attack (Im not counting nova (PBAoE) or power burst (miniscule range)) 
As far as I can see it boils down to maths:
Solo a lot : Regen (flat rate of damage mitigation)
Team a lot: AV (%age of incoming damage mitigation - more enemies, more effective).
Always go with concept first tho1
Invuln is about getting the mob around you to give you the defence (it's really a def based set, not a resistance based one) so you don't get hit. Regen is all about healing back the damage the bad guys give out in various ways quicker than they can dish it out, all the time dishing our your own damage. I've only tried Regen to about lvl 16, Invuln to lvl 50 as you can see, and even at low levels I much preferred Invuln. Only pain is the end cost to begin with. only with Invuln can you get into the middle of a mob and laugh as they can't hit you.
Defiant 50's
Many and varied!
@Miss Chief
I wanna make a scrapper but can't decide on the secondry i used to have a dm/regen scrapper and i got a inv/ss brute and i like both secondrys but haven't tried out the inv on a scrapper yet, is it worth taking instead of regen? i feel regens are a bit squishy.
Many thanks.