I am using the 7BSST2 monoblocks about 10 years old. Previously I had the BP20 and 4BSST which sounded a little darker than the current set up. My Infinity Kappa 8 speakers are very hard to drive so the more juice the better. You may want to check out the DH Labs Air matrix interconnects. I just love all their cables but those have been real winners with the locking phono plugs and open literally airy sound.
Anyhoo as they say it will be interesting to hear your comparisons. I'm sure the 17 is wonderful too I do wonder if the MPS2 is an improvement though over the 17 power supply. Also the 17 can have an apparently nice phono stage added which is a plus depending on how proud Bryston is. Their separate phono preamp is a bit pricey.
Anyhoo as they say it will be interesting to hear your comparisons. I'm sure the 17 is wonderful too I do wonder if the MPS2 is an improvement though over the 17 power supply. Also the 17 can have an apparently nice phono stage added which is a plus depending on how proud Bryston is. Their separate phono preamp is a bit pricey.