Upgrade from Emotiva XPA1 to Bryston 28bsst2 or Pass X350.8

Hello everyone, this is my first post. I have fairly recently begun building up a system after many years away from owning any decent home hifi equipment. I started off with Maggie 1.7 speakers running off Emotiva XPA1 mono-block amps. I am now driving my Revel Salon 2 speakers with the same Emotiva XPA1 Mono-block amps, with a Bryston BP-17 pre-amp. I have been using the Emotiva amps for a few years, as starter gear for re-entering the hobby, however I would like some good feedback on potential replacement amps that would significantly improve the already amazing sound quality of the Salon 2 speakers. I was thinking either Bryston 28bsst2's or Pass X350.8 or similar. What do y'all recommend for driving the Salon 2 speakers. I would like to hear better sound for jazz at low to mid listening levels, but still need enough power for rock music at higher levels. Thanks.
Also check out the Parasound Halo range. :)
Without knowing the rest of your setup it's hard to say whether the amp changes is really a good value for your money.  Either amp may be better than the Emotiva, but possibly only a subtle upgrade within your system context.
I can't comment on either amp you're considering but I had a pair of the Emotivas on hand for a couple of weeks.  I directly compared them to a Theta Intrepid and a Cambridge Audio 840W.  Speakers were BG Corp 520dx or Meadowlark Audio Herons (hot rod version).  My cables are all DIY but they are quite good and all plugs on the power cords are either Oyaide 046 or IeGO's top 8095.  Sources included a Modwright Oppo BDP-83SE with tubed power supply or a Cambridge 851C both driving the amp(s) directly.  The Theta was run 4 channel to biamp each speaker. 

To make it brief, the Emotiva amps were clearly outclassed by both the Theta and the Cambridge.  The Emotiva bass was full and I could see some speakers sounding better, bass-wise, with the Emotiva over the Theta but, the Cambridge had a much tighter, more articulate bass range with greater impact.  No comparison there.  And that was the closest the Emotivas got to either of the other amps. 

The Emotivas were considerably less detailed than the others with less distinct image outlines and never created any sense of depth in my systems.  They were always 2-D and never palpable but that's not to say they weren't musical.  They were always pleasant to listen to but, compared to the Theta and the Cambridge, they weren't at all engaging as I was always aware that I was missing quite a bit.  Pulling the Emotivas from your system for the Pass should be a big upgrade if you've good enough cabling (junk cables are always a bottleneck in a potentially good system).  I haven't heard the Bryston you mentioned but wasn't impressed with the 4BST as it just sounded dry to me (but that's been many years ago). 
I’ve heard the Pass X250.8 in my system. It was a lovely, liquid sound, slightly midrange-forward to my ears and easy to listen to in the treble. I would have kept it, but I couldn’t tolerate (in a basement room) the 400W of heat it puts out at ldle. If anything, the X350.8 should sound even better, and run even hotter.

For years, I used a Bryston 14B SST, and I thought it was the best amp I’d had. I still miss it. Reviews of the 28B say it’s in an even higher class in the treble especially, and the bump from SST to SST2 is supposed to add a little more to that. Comments about a 4BST, though certainly offered in good faith, won’t reflect the sound of a 28B SST2.

So, I think you have named two great choices, and the only way to know which one is right for you is auditioning in your own system and room.

I would also suggest the Parasound Halo line, and for mono blocks, the JC1.  I went from an Emotiva XPA amp to a Halo A21, and everything got better.  The imaging, the bass, the vocals, the highs, it showed how entry level the Emotiva amps are.  
Bryson 28sst mono blocks excellent. Owned a 14bsst at one time and buddy just purchased new 14 b cubed and is very happy. 
Depending on your budget... I'd look at all of the following.

Pass XA series
Mark Levinson
Parasound JC1's
Welcome! brystonkiwi

at this level of power amplification, you must get a demo.
The natural choice would Bryston -if you are keeping the Bryston pre-amp?

Happy Listening!
Take a look at Usher R1.5 too.Great amp with a great sound and power handling. It smoothers amps 3 times its asking price.
This might’ve been pure marketing but Revel speakers are most frequently paired with Bryston components, particularly amplifiers, at most audio shows. I have heard the big Salon 2 with the 28B SST2 and the sound was incredibly detailed, full, and evenly balanced across the spectrum, sort of untuby. Some may consider that dry or too technical. I found it accurate and natural.
Thank you everyone for you helpful responses. Sorry I had not responded sooner, as I have been offshore. I have heard mostly good comments in the past about the 28bsst2 series amp and the used prices seem to be coming down now that the cubed version of this amp is apparently nearing release. It's hard to ignore the great following the Pass Labs X350.8 series Amps seem to be earning across this and other web sites though. I guess I may have to do a bit of traveling to go see if I can hear both amps and see if I like the sound of one better. Should I expect either amp to have significantly more 3 dimensional sound than the XPA1 amp? Assuming good and equivalent cabling?
Hi brystonkiwi,

I have Revel Studios. The best amps I've driven them with are Vincent fully balanced SP-998 Mono blocks. They drive  the Studios effortlessly and have the best grip on bass I've ever heard from Power Amps. I would think they would be a great match with the Salons. I have an Emo XPA-2, and while it is good bang for buck the big Vincent's are in another stratosphere, better.

I hope I'm not offending but would seriously look at a better Pre-Amp, perhaps even before upgrading your Power Amps.