I think the newer b-60's use the SST amplification design. That might be a big improvement over the original one, so if you go used try to get the SST version. I've never heard either b-60 but I owned the amp that the original was based one. It had great authority and I like it a lot but had a bit of grain compared to the competition of today.
I'm almost afraid to bring this up - heck I AM afraid to bring this up but I will anyway: DK VS-1 mk II's are showing up used, and if you saw my review (www.dkdesigngroup.com/audiogon/review), I really love the sound of this unit once you upgrade the input tubes.
I can't say how it would compare to the latest generation B-60 or the others you mentioned.
Art
I'm almost afraid to bring this up - heck I AM afraid to bring this up but I will anyway: DK VS-1 mk II's are showing up used, and if you saw my review (www.dkdesigngroup.com/audiogon/review), I really love the sound of this unit once you upgrade the input tubes.
I can't say how it would compare to the latest generation B-60 or the others you mentioned.
Art