Not going to guess because I have never owned either amp.
Having said that, let me leave you with a couple of thoughts. (1) The Ref 210 is just that -- a reference grade amp. I think that counts for something. (2) The Ref 210 has a much larger power supply than the VTM 200. This is another important spec. (3) The Ref 210 can handle KT-120 tubes. I think the KT-120s sound much better than the 6550s. (4) The Ref 210 was just phased out last year. The VTM 200 is a little longer in the tooth. A big assumption, but maybe the Ref 210 incorporates more modern and recent tech innovations.
The ARC customer service folks, like Kalvin Dahl, are pretty straight forward about their products. I'd give Kal a call after the holidays and ask him.
Happy Holidays
Bruce
Having said that, let me leave you with a couple of thoughts. (1) The Ref 210 is just that -- a reference grade amp. I think that counts for something. (2) The Ref 210 has a much larger power supply than the VTM 200. This is another important spec. (3) The Ref 210 can handle KT-120 tubes. I think the KT-120s sound much better than the 6550s. (4) The Ref 210 was just phased out last year. The VTM 200 is a little longer in the tooth. A big assumption, but maybe the Ref 210 incorporates more modern and recent tech innovations.
The ARC customer service folks, like Kalvin Dahl, are pretty straight forward about their products. I'd give Kal a call after the holidays and ask him.
Happy Holidays
Bruce