Pass Labs X350 vs X250.5

I'm considering a pre-owned purchase of either the PASS LABS X350 or X250.5 Stereo Amplifiers, to power a pair of Wilson Audio Sophia2 Speakers, in a relatively large listening room. The costs are close enough, as to not be a factor. I'm leaning towards the X350 (previous model) because it has considerably more overall power (700-wpc vs 500-wpc into 4-ohms), and more than double the amount of desirable Class A Watts (40 pk Watts vs 15 pk Watts) over the current model X250.5

Unfortunately, I can't demo. these Amplifiers side-by-side. Any suggestions would be appreciated.

Thank you!
I just purchased a Pass Labs X350.5. I have auditioned a x250.5 and an x350 in my system. I am using Apogee Duetta Signatures which have a 3 ohm load nominal. They need lots of current. The x350 was cooler sounding and not as involving as the X250.5. The x250.5 is a much better sounding amp, However the I was able to find a great deal on an x350.5 and was not able to audition it until I purchased it, but the seller said if I did not like it they would take it back, no questions asked. I found the x350.5 and the x250.5 to be very similar in sound their quality the 350.5 was a bit better and drove my speakers the best out of the three. If I had to live with a x250.5 over the original x350 I would take the x250.5. It might not plays a loud but it sounds much better than the original x350. There are a couple of x350.5 on audiogon and they are between $1200 & $1500.00 more than the the x250.5. I would scrape the difference and get the x350.5. you will be much better served with better sound and more power. The .5 series amps are much more musical. the older amps sound good as long as you do not compare them to the newer Pass Labs amps.

I got to listen to the X350 and X350.5 side by side at a friend's place before pulling the trigger on the X350.5. (He sold the X350 and kept the X350.5) I still have my Pass Aleph Os that I just love dearly. The original X series (non-.5 series) strayed away from what Pass was famous for and resembled more of a stereotypical SS amp, sterile and cold sounding. The .5 series brought back that midrange magic that the original Aleph amps were known for without any sacrifice in terms of dynamic and bass control of the non-.5 series. We both thought the difference warrant more than just a ".5" designation.

If your Sophia is not power hungry, go with the X250.5, otherwise spring a little bit more dough and go for the X350.5.