Just some comments from a Robots/Dark MM who has reached level 35 so far.
 STAMINA: 
I would love this power, and I may get it after some testing on the test server.  I have played through 35 levels without this power and until they open up the 40+ levels i probably wont take it.
     1) Resting in the middle of the Summoning/Upgrading cycle will get you the endurance you need just as quickly.
     2) I run 3 toggle constatly; Shadowfall, Assault, and Tactics and still gain end (though Darkest Night makes that a losing plan)
NO WEAPONS:
I support Sapph's view on this, just because you didn't take any of the Pulse Rifle attacks doesn't mean you are not busy (see below)
BOT SLOTTING:
If there is any topic that draw more debate from MMs than this I don't know what it is.  For the record;
     Battle Drones:   2 Acc, 3 Dmg
     Protector Bots:  2 Acc, 3 Dmg  (start hating me now) 

     Assault Bot:      1 Acc, 3 Dmg
Since i have no personal attacks (still see below),  my bot's #1 purpose in life is to deal damage.  With this build I hit+3 and +4 minions almost always, and can hold my own Vs. one or 2 +6 level minions or a +7 minion. (Side note: xp seems to be capped at +5 levels i.e. a +5 minion and a +6 minion both give the same xp now. anyone with solid info feel free to PM me)  (Side Note 2:  I will be adding one End Reducer to the Protector Bots, since the are frequently running out of end now)
 
HEALING: 
Since many of you are looking at the last Paragraph and decring the lack of Healing slots on the Protector Bot i'll bring this up now.  Twighlight Grasp is a wonderful area heal with the same range as the Bots' basic attacks.  Even so I supplement this with  
Aid Other this powr was hard to get used to but i still stand by my choice.
     Twighlight Grasp:  2 Acc, 3 Heal, 1 Range
This gives the heal a range greater than the bots so i can stand behnd them if i want.
 
AID OTHER:  (yes i know i had this up above) 
This power bears a little explanation:  
      

It can be used on other players, or other pets.
      

It recharges faster than Repair.
      

It doesn't require a target to hit as Twilight Grasp does.
      

 It can be interrupted which takes getting used to.
      

 It can be interrupted (it's a big drawback see COT quicksand).
      

 The range is much shorter than i belive it should be, like 15-20 feet.
So why do i still have the power?  The answer is simple, I love it.  It makes a great companion to Twilight Grasp in that i can be used between mobs.  It heals your teamates (always good in CoV) because you know they don't stay in range of Twilight's heal.  Aid Other will heal a good deal with just one slot, more than the Protector Bot does unslotted.
 
HOWLING TWILIGHT: 
I have this power and probably don't use it as much as i could (my teams tend to not have very many deaths).  I have an SGmate that swore by this on his pre-i6 Dark Defender as his main attack power.   I know this power can be used solo, but i have other options (you know the drill, see below).
 
FEARSOME STARE AND PETRIFYING GAZE: 
These 2 attacks are part of my opening salvo.  These are my goto attacks (ok i do have one attack power, i took Air Superiority just to feel like I was doing dmg).   Fearsome stare is more useful if you group alot.  Gaze is better solo because it's a hard lock and the spawns tend to be much smaller.  Gaze, even with the nerf is still strong and can keep (with 2 Hold SOs) a minion or Lt held while your bots finish off the other.
I may end up posting a seperate guide on Bots/Dark or just one focusing on Dark Secondary or MMs.  Look for it in the future.