Pass Labs X-250 vs. X-600

Can anyone tell me how much different these sound. I own a X-250 and am considering buying a pair of X-600.
In the original X-series the gem sonicly is the X-600s. Not just more power but a significant improvement in all factors such as details,timbres,soundstage,etc. However, you might want to try either a new X-350.5 or when it comes out shortly,a pair of X600.5 monoblocks because the new X.5s are a significant shift towards sonic bliss! The X-350.5 is great and you could get one at the price or near the price of a used pair of X-600s,which I think don't sound as good as the new X-350.5. Hope this helps.
To answer your question, there is a greater sense of ease to the sound/music with the X-600s. More air, more dynamics, better defined bass, etc, etc. I owned the X-250 for several years and it does what it can do extremely well especially for the used prices now but you'll have to decide for yourself if the extra %percent improvement is worth the extra $$$bling!

Happy Listening.
I would highly recommend you listen to the 350.5 before you make a decision. I have owned one for six months and am completely enamoured with it. The .5 improvement isn't subtle at all. As much as I liked my 350, I couldn't go back.

I have a pair of X350.5 and they are wildly powerful, the needle never fluctuates...this is my first experience with Pass, but i've owned SEVERAL high end/high power amps, and I'd be surprized if any system needs more power than this model....
The X250 (and smaller X amps) have feedback for bass control. The X350 & larger X amps don't.
Some purists don't like feedback. I hear an X150 everyweek at my friend's house, it sounds very, very good, to me.
I've heard the X350.5 at my local Pass dealer. Everyone agrees it is a big step up in sound quality, over the original.......
The X150 my friend owns has the same plastic cased output transistors as the new .5 series amps.