PassX-250 vs PassX-350


I have the X-150. I'm looking to upgrade. I love the 150 but I want more power. Is it worth it to spend the extra loot on the 350,or is the 250 a close sonic match? Also how will those amps match up with a BAT tube preamp? I appreciate any help or suggestions.
krelldog
Thanks Bhouser,and everyone else for the advice. The X-350 is 9K,but the used price recently is around 4K(actual ads)If I sold my 150 it might only cost me a couple grand more for the 350. Regardless I'm sold on Pass,and my decision is narrowed down to the 250 or the 350. I probably can't go wrong with either.
I spoke to Peter at Pass and he helped me with some of the differences between the amps. The x150 and x250 have similar circuit designs with only some localized feedback around the output stage. The X350 and larger amps have the zero negative feedback characteristic which adds to their lushness and overall neutrality.
Nutella, that's new to me. I never heard the X150 and 250 use feedback while the larger ones don't. I do know, for a fact, all X amps employ a small amount of feedback in their supersymmetry circuits to help equalize distortion matching. As far as I have read, that's all.

Still, when I switched an X150 for X600 monos on 4 0hm speakers, I noticed more than the expected bass improvement. the midband was both warmer and it had more body. It is my guess the class A operation of the X600 accounted for the different performance. That is why I am voting for the X350 in Krelldog's case.

Bhouser, I am running $1500 speakers on $16,000 amps. If the speaker does everything you want, and it asks for the power, you feed it.
Muralman1,
I thought that was what I said. Rather, what Peter said.
For $4000 used I'd also opt for the X350
Good for you. Peter (right up the hill from me) might not like me saying this, but it's their fault - Pass Amps are so dependable, buying used is a safe bet.