Thiel 7.2 or Revel Studios

Between the two, I prefer the Thiels because they are so revealing. For my taste, the Revels are too laid back. I fully support Jdevine's observations about the great customer service at Thiel. But, from my experience, the Thiels can be a bit harsh sounding when partnered with a bright amp -- synergy is critical with any speaker. When I owned the Bryston amps, I needed to move to MIT speaker cables to find the magic with my Thiels. If the Krells falls into the "bright" category, you may want the Revels if you don't want to change too many other parts of your system (it's been a long time since I've heard Krells so can't remember how they sound). Otherwise, my vote would go to the Thiels based on my tastes.

Revel Studios are more musical to my ears. Thiel has always been a bit grating on my ears. FWIW.

Two clear, detailed, good imaging, well balance sounding speakers that are very musical sounding. I've sold Thiels for years, and have experience with the Revels somewhat, and heard at shows and clients homes as well.
Both probably do best with slighly different gear selection choices from what I recollect. But that goes with anything.
I think you should try whichever is more accessable and or apractical for you(unless you like the looks of one over the other).
If you like the sound, then stick with em. But make no mistake, you can get good balance out of either with careful gear selection.
To me, these are both the typical "high end sounding" audiphile speakers these days...pretty, clear, detailed.(like Wilson's, Talon's, Maggies, Joseph's,Apogee's, etc)

Keep 1 fact in mind: Revels take hundreds of hours to break in. Have a lot of patience if they don't sound as good at home as the demo's in the store.

I agree will all of the above. One other consideration is your room. Thiels like very wide spacing, with ample distance to side walls, pointing straight ahead. Revel is a little less picky on placement, but if you get the Thiels dialed in, I think they have the edge.