I own both the D200 and a pair of Wolcotts; they are very different beasts, each is truly superb in its own right when used with the proper speakers. I am not familiar with the SA 250 but am very familiar with the SA 100 run in mono, both class A and AB. The SA 100's are the antitheseis of the D200, slow, dark, lacking in transparency but powerful at the bottom. Even in a bi-amped system, the SA 100's would not be my choice (I have heard that the 250's are a completely different amplifier and much, much better). The major weakness of the D200 is its ability to deliver current into a tough load. With a reasonably efficient speaker like the Kharma's, it is excellent top to bottom. Driving less efficient dynamic speakers (such as the early Rockports), its bass suffers; however, above that it is still wonderful. It is, perhaps, at its very best in a bi-amped situation, such as Quads with separate subs. A last thought, the D200 is a champ at imaging; however, the way in which it creates the soundfield is different from that created by really superb tube amps and to me less believable. Likewise, its midbass is leaner than that of a good tube amp. Not so much better or worse as just different.