Take ID!
Only thing where Stimulants better than ID is that it offers sleep protection and ID does not but you can sort that with a heal if needed.
Stimulant recharges 3 times as slow as ID, duration is 25% shorter, uses almost 3 times as much endurance, it's interruptible + ID gives smash/energy resistance.
Think that about covers it.
NinjaEdit: Having said that...I wouldnt necessarily take ID. Even if its a good power it's one I only take it if I can fit it in my build. Choice between the two then it would always be ID though.
SingStar:
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CRACK68:
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Lionsbane:
"You know me.Ever the realist"
There is the chance to slot Flash if I don't take ID.
Is it any good?
Main Heroes: Dark Requiem 50+2, EarthGlade 50, Natures Wrath 50, Imperion 50, Spectral Echo 50, MydKnight 42, Flash-Point 42, Cascade Effect 39, Scirrocco 35, QuantunStarburst 41, EarthLight 35, Silver-thorne 32, StormFrost 35
Up and Coming: , DragonStorm, Metalworks
Take ID *and* slot Flash as ID doesn't really need slots.
@Jay Leon Hart
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Increased Density indeed. I only think about getting Stimulant on my /Rad controller but took stealth instead 
As Jay said ID don't need any sloting at all.
It's funny how many Kins feel that ID is skippable... but personally I look on ID as a good Resistance buff first and decent Mez Protection second. I tend to use it on Tankers or Blappers for the Resistance buff.
An extra 30% resistance to Energy and Smashing damage is nothing to sneeze at, particularly from a Controller. Defenders get 40% from it. Yes, it only lasts for 90 seconds and Kin is an active set, but if even you can keep it on only 1-2 allies (Tanker --> Empath --> Blapper is my order preference) it can make a big difference fighting most foe types. Very useful versus AVs if you find yourself with a struggling INV or Fire Tank.
And speaking from the POV of an Earth/Kin... combined with the resistance pet IO, it also turns my Stoney into a rather respectable tanker (see below). Personally I'd sooner drop Speed Boost than ID.
Animated Stone's Resistances with Slotted ID + the Sovereign Right +Resistance Pet IO:
+ 110% Psionic Resists (100% base + 10% from IO!)
+ 100% Energy Resists
+ 90% Toxic Resists
+ 80% Smashing Resists
+ 70% Fire/Cold/Negative Resists
+ 60% Lethal Resists
[ QUOTE ]
Yes, it only lasts for 90 seconds...
[/ QUOTE ]
60 seconds Mael... 
SingStar:
"Extremists LOVE to fish to get us annoyed so we break the forum rules."
CRACK68:
"The origin of life wasn't planned either, should all life be declared a bug and wiped out?"
Lionsbane:
"You know me.Ever the realist"
[ QUOTE ]
[ QUOTE ]
Yes, it only lasts for 90 seconds...
[/ QUOTE ]
60 seconds Mael...
[/ QUOTE ]
Meh, Po-tay-to, Po-tah-to... I just go by when it starts blinking... 
2 Sec Cast time, 3 sec recharge. Even a busy Kin shouldn't have any trouble keeping it on 1-3 allies.
I'm not suggesting that ID should be used as a proactive mez protection buff, because frankly buffing all the squishies every 60 seconds gets old real fast. But extra resists for toons that are likely to pull aggro is way helpful, and if you're feeling generous to the Empath you can trade him a perma-ID for a perma-CM! 
[ QUOTE ]
Only thing where Stimulants better than ID is that it offers sleep protection and ID does not but you can sort that with a heal if needed.
[/ QUOTE ]
Errm and confuse protection too afaik... but on the other hand, ID offers kb protection, which stimulant doesn't
Increase Density is a nice place to pop a Steadfast Knockback Protection too. :3
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Member of Paragon/Rogue Knights
Arc: 60092 - Supa Rumble in the Park
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-- High-Roller
Currently at lvl 28 on my Illusion / Kinetic and wanted opinions on getting either Increase Density or Stimulant?
Are there any pros and cons for either?
Thanks in advance
Main Heroes: Dark Requiem 50+2, EarthGlade 50, Natures Wrath 50, Imperion 50, Spectral Echo 50, MydKnight 42, Flash-Point 42, Cascade Effect 39, Scirrocco 35, QuantunStarburst 41, EarthLight 35, Silver-thorne 32, StormFrost 35
Up and Coming: , DragonStorm, Metalworks