Which Amp Is Better ? ?

Pass Labs x-3 for 125x3 and x-150 for 2 ch
or x-250 for 2 chan

You might also consider McCormack, although I'm not sure if he's got a 3-channel amp out yet--check the website. They're very reliable so if you can you might want to check out some used McCormack amps. I bought a DNA-0.5 Rev. A for $1600 and they still seem to pop up every once and a while, but the 3-channel amps seem harder to come by on the used market. Steve McCormack has told me his current amps incorporate up to his Rev. B level of modifications, which makes them a relative bargain. Best of luck.

Tim

On balance, I would recommend the Bryston amps over the B&K's: better sound quality, better build quality, and a far superior warranty (20 years). If you decide to go with the Brystons, and you have smaller (i.e., not full range) center and surround speakers, you might consider the pairing the 4B-ST with a 5B-ST rather than 6B-ST. The 5B-ST has actual power output of 150 wpc, which is usually more than sufficient for the center and surround speakers. I have been using a 4B-ST and 5B-ST combo and am very pleased with it -- fine sound quality, and more than enough power.