McCormack DNA1 Rev A or Bel Canto Evo 2

I have the Vandersteen 3A Sigs and the Bel Canto Evo 2. What I have sounds fine to me, but I've read alot of good things about the McCormack revisions and you can pick them up pretty inexpensively. The chassis of those units can be about 10 years old, however. I used to have a DNA .05 which was a bit thumpy in the bass, but which I otherwise liked. What would you recommend?
McCormack have been renown to be excellent partners with the speakers you own. Choose between the DNA 1 revisions or even the new DNA 225, can be had at about your price range. Thumpiness of bass has a lot to do with the set up of the speakers (not enough distance from the backwalls) As the owner of the newer DNA 225, I say that it is dynamic, lighting quick and neutral, but never cold. I do not think that the Bel Canto will be able to have the same drive, due to the power supply design. Can always have the DNA upgraded later down the road for a SOTA amp.
I have both amps and cannot understand why you are considering a change.