What demon should I use in raids asDemonolagy Warlock. Wotlk 3.3.5a

I made a warlock on Icecrown realm, Wotlk 3.3.5a. Just 3k gs atm.

I will play it as Demonolagy warlock.

I was thinking what's the best pet to use in raids as demonolagy warlock? Most people say Felguard, but aren't he going to die fast in raids like ICC 10/25, ToC 10/25 ?
Also I think Imp is making more dmg, than Felguard. One more thing is that if I use Imp in raids I will save 6 talents, that are normally spent on talents needed if you use felguard.

[Demonic Brutality] these points will be used for [Improved Imp]
[Fel Synergy] saving 2 points from here, because why would I want to heal an imp?
[Mana Feed] saving 1 point, imp is always full mana.

In raids your felguard will provide a raid wide SP buff when it crits - so that.

The most important thing I can tell you:

You should be aware of the fact that you lack the experience and the knowledge about the topic so there is no point creating new theories.

Use FG because it is better (btw Imp crits also trigger Demonic Pact).

http://web.archive.org/web/201402100...howtopic=99187 --> read this if you are curious :)