Classe CA 400, Pass Labs X250 and X350 comparison.

I am thinking of upgrading my amplifier. I have a Bryston 4B-ST. My system consists of a Classe model 6R preamp, Coincident Total Eclipse speakers, Theta Miles balanced cd player along with a Arcam CD92 cd player. I am leaning toward Pass Labs X250 or X350 (more power). Along with a cheaper alternative the Classe CA 400. I like blues and classic rock for music choices. I am looking to improve dynamics,detail,wider/deeper soundstage and maybe improve mids and highs. I would greatly appreciate any comments, opinions and suggestions regarding these amplifiers. Offering suggestions about how any of these amps could improve over my Bryston are important. I think Bryston has a good reputation for having good bass, would the amps I have suggested improve that? Thank you in advance, Somebody please respond. One other note the Pass Labs amps have the X250.5 model is it a notable choice over the other two. There is quite a considerable price increase to purchase one?
I have my system set up in my basement. The main part is roughly 24X40 with tile floor, acoustic ceiling and paneled walls.
I have a Pass X250.5 and find it to have nearly complete control of the bass. Much like a krell amp that I also own.

I have found the Classe amps to be terrific in the mids and highs, but seem to be slow or sluggish in the bass compared to Krell or Byrston.
hi everyone
I have thought about selling my classe ca 200 and abandon
the idea of biamping and going with one larger ca 400 . I
am a big classe fan and like rshad0000 said , classe amp
seem to be a bit slow & sluggish in bass responce but the
truth is classe tends to be very warm & tube sounding .
a far cry from like krells .
The Pass X.5 series is a big improvement over the original X version. The X350 can be described as cold or analytical.
Thats why there is such a big price diference in the used prices for these units even though the original retails prices were about the same.