As far as know http://tesnexus.com/downloads/file.php?id=13939 is a purely comsetic mod and Troll the interior decorator has turned it upside down.
OOO adds lots of clutter and a group of baddies including a boss characters. KOTN also adds a group of baddies including a boss characters, and also quest items.
Is it overkill with both KOTN and OOO? I think OOO was made before KOTN came out, so probably would Oscuro have toned it down if he made OOO with KOTN in mind.
What is peoples' experience? I assume many have played through with both OOO and KOTN installed, but not som many with all three mods installed.

I have yet to explore that cave while running OOO. I have run through it with KOTN active. I am not familiar with the mod you mention. At some point I will explore that cave with both OOO and KOTN active.

I haven't played with all three but will this time around. I doubt CDEP Underpall Cave conflicts with OOO but haven't checked either ingame or in the CS.

That both OOO and KotN have boss fights in the same section isn't ideal. For one thing, it's possible for a low level char to do the KotN quest line up to and including that point, but with OOO that stage is more or less impossible for low level chars. From an OOO perspective, the KotN enemies really doesn't make that much of a difference when it comes to difficulty. The main issue is rather that it's a bit confusing and "immersion breaking" with two separate boss fights in the same section IMO. Which could be said about using Lost Paladines of the Divines and some other quest mods with OOO as well.

Thanks for the info.
I guess one problem with OOO is that it's everywhere. I've already patched OOO to work with the other other CDEP mod - http://tesnexus.com/downloads/file.php?id=14036. In that case it was easy, since OOO only adds its own leveled enemies and some loot and clutter, which I just disabled. But with Underoall Cave it was a bit more difficult to decide since it included bosses with scripts attached to them. But as far as I could tell when I looked in TES4EDIT the boss was not connected to any quest.
So I guess I will patch both Underpall Cave and Lost Paladines as well, so that they don't get pwned by OOO.

I just did Underpall with OOO, KotN and CDEP Underpall Cave - and I didn't notice any conflicts at all between OOO and CDEP.

When I was developing that cave I had both, OOO and KotN installed, so just paid attention to not brake any things there...
and during the testing those fights were challenging and interesting for me...

And it was in fact extra challenging this time around as my char was surprise attacked by a certain enemy added by another of your excellent mods. :toughninja:

Anyway, CDEP Underpall is exquisite. :thumbsup: