Pass Labs Power amps choices


I am selling my Krell EVO components and moving over to Pass labs.
I just snagged a very nice X-1 for a song and now need a power amp to move my Revel Ultima Salon 2 speakers.
So my thoughts are either 250 or 350 stereo amps. Question is...how much different/better are the .5 and .8 varieties over the older x-250 or x-350 amps?
Many thanks.
Aloha!
mauidj
If you get the .5, you will lust after the .8 forever.  Just get it now and never look back.
Read my review of XA200.8 at Dagogo.com 
I discuss the difference sonically between. 5 and .8 series. 
If you don't believe because I am a reviewer,  shame on you!  ;)
I'm thinking that although the 250.8 would be a nice upgrade over the 250.5 that it would not be worth that type of money to do the upgrade. I had my 250.5 repaired a few years ago and it is working nicely. It would take me several years to pay back $10,000 so I will just enjoy my 250.5 as it is. My pre is an X1 which matches nicely to my amp and my speakers are Hales Transcendence 5"s which are nice. I just recently upgraded all my cabling from Cardas Golden Reference to Audio Art Statement interconnects, speaker cables and power cables. The upgrade was nice and I am very pleased with the results. I also upgraded my PS Audio Perfectwave MK II dac to a PS Audio Directstream with Bridge II. I am definitely enjoying my system in a way I never enjoyed it before. The Audio Art Statement cables were a huge upgrade over the Cardas Golden Reference and the power cables are much nicer than the previous cables I had. To be truthful I'm not that itchy to upgrade my 250.5 at this point. I believe the total cable upgrade throughout my system top to bottom was an upgrade I do not regret.
As I understand it the .8’s have a slightly more muscular output with a more tailored harmonic content, on the other hand the .5’s are more harmonically neutral (than the .8's). I believe Pass Labs will still offer .5’s on request.