ascend sierra tower with raal or Focal Aria 936

I don't have the towers, but I do have the Sierra 2's. I find them very non-fatiguing. The RAAL tweeter is excellent.

If you heard Focal speakers are bright, you heard that from someone who hasn't heard Focal speakers within the last 5 years or so.  Arias aren't bright at all and neither are the Sopras (properly set up).

I've seen that thread on AVS and I'd take that guys opinion with a grain of salt.  Very novice listener and even he was bothered by the sierras at first and "learned" to like them after all the AVS users convinced him to essentially.

Just find a Focal dealer to hear the Arias at and you'll see.

I own a pair of 936. Fatiguing? Let me put it this way... More than a few times have I been listening to an album and found myself listening beginning to end and still wanting to hear more. They're extremely easy to listen to for great lengths of time, yet they're thoroughly engaging. I completely agree with the praise heaped on them in this thread.  

Contuzzi:
I've seen that thread on AVS and I'd take that guys opinion with a grain of salt. Very novice listener and even he was bothered by the sierras at first and "learned" to like them after all the AVS users convinced him to essentially.

That's not what I got out of that thread at all.  The OP preferred the Sierra's in most of the songs in his speaker comparison, and there were fanboys for both the Sierras and the Focals trying to convince him.  I was impressed that this novice brought in some acoustic panels to improve the sound in his room.  That was not a novice thing to do.

I'm wondering what cougar4u decided to do, because I'm considering the Sierra tower as well and reading that it is being compared to speakers that retail for $4000 is impressive to  me.

Unless you're buying those Ascend at some sort of discount, you're not looking at a speaker in the Focal 936 price range. You're talking more like a couple hundred away from 948's and I'm sure you can talk a dealer down a couple hundred. Personally, I think the 936's are 98% the speaker the 948's are. 
My antique rig has a pair of ESS AMT1's in it and I've heard a lot of AMT-type speakers. I like AMTs a lot and if you really want to burn 4 or 5 grand on something with a pair of them, go listen to a pair of big ESS with that massive dipole on top. They do things no other speaker does so we'll. 
All of that said, ribbons and AMT's are far more fussy about placement than the Focal will be, though 936's will want some consideration and tweaking. I'm also skeptical of the dispersion claims made of AMTs. I think they're better than ribbons, but they have practically no forgiveness for vertical off-axis listening. It basically doesn't matter with the Focals. Nobody is listening to 936's or 948's on tweeter axis unless they play in the NBA. 
Just some considerations....