Stehno hasn't heard the ST140, or the M200s, so his quick use of the mid-fi tag seems fairly liberal to me. These are super amps, and as Upstateaudio pointed out, they do differ (in my opinion, significantly) from the newer B&K's. If someone believes B&K to sound like Yamaha, Denon, Pioneer, especially without an audition (not a unique opinion), I suggest they form an opinion on something other than price or hearsay. Especially with respect to the older amps.
My one point of caution is that the (current) ST2140 has low current and low damping factor. I second the recommendation that you consider a McCormack, just for comparables - I've owned both B&K and McCormack, and couldn't recommend one over the other for you, as they are different, but both can provide great sound with huge value.
My one point of caution is that the (current) ST2140 has low current and low damping factor. I second the recommendation that you consider a McCormack, just for comparables - I've owned both B&K and McCormack, and couldn't recommend one over the other for you, as they are different, but both can provide great sound with huge value.