I'm really not sure when to do this. I wanted to wait until I was in ToB, since I wanted Sarevok in my party.

Well, now I'm here, but can't really decide where along the way to do the keep. Will I be powerful enough to tackle the keep after facing Gromnir (I think that's the earliest you can go in ToB)?

Should I wait longer?

It seems like there's never really a point in the story where you're "supposed" to go there, so I'm just wondering when my fellow IWers check out the keep.

TIA

i tend to go after completing the seige camp. it's convenient as well since you are powerful enough to make it through.
Depending on how high your party's level is, you can visit the keep safely. Post your characters and their stats.

Hmmm...I am starting Throne of Bhaal (finished it many times before but long ago), and I remember entering it quite quickly. Like "Lord" said, you shouldn't have a problem with it. When finished with Shadows of Amn, your party should be strong enough to face the place. I would imagine if you can kill Gromnir and his minions, then the Watcher's Keep will be beatable--challenging (which is good anyway) but beatable. To be safe, though, I would make sure a lot of resistant spells are available, as well as some good potions, just in case...Lots of evils lurking in there...

I've decided to give it a shot right after facing Gromnir. Right now, I'm about to release the Chromatic Demon (do I sense a battle?) Krunchy: Fighter/Mage/Cleric 16/15/17
Jaheira: Fighter/Druid 19/14
Minsc: Ranger 22
Keldorn: Inquisitor 22
Imoen: Thief/Mage 10/21
Sarevok: Fighter 20

Imoen just got Cure Light Wounds and Larloch's Minor Drain. I think that's pretty cool!

I've bounced out of this place about 12 times already to see if that annoying imp can make me some new crap!

i did it straight after gromnir. its my first time in TOB, so it was quite fun and chanlenging in some parts, while easy in others

You will probably be able to take on all of the Keep, but remember if you get stuck you can always abort and come back later.

Krunchy...Ah yes, with Keldorn and Sarevok, you've got two good tanks. Do you have that cool sword for Keldorn (Carsomyr, I think it's called)? Boy, that's a great sword! Kicks butt against evil--part. liches! That weapon right there should help you with Watcher's Keep...Do Saravok and Keldorn argue with each other? I can't remember...been so long....

Sarevok has argued with all of my NPCs. I have been told that I need to take him at least once because his banter is great. I'm loving it so far!

Sarevok is a great NPC. The only reason not to take him would be roleplaying. Would a good aligned PC allow himself to trust someone of the likes of Sarevok?

I do parts of watcher's keep at different times. When I feel like I can't do a level, I go and come back later.