Best Mid Fi Amp from 90s to today. Look

Ive heard the BK, Spectron and the Sa220. I prefered the sa220 by a landslide, however I would have reservations buying one used, as the ouput devices are no longer available and from what I understand if they go out its game over for that amp unless you want to spend quite a few $$ with the M Elliot upgrade.

(please pardon the run on sentence)

I've heard the Classe 10 (not the 15) and the DR25. Both are excellent. I prefer the DR25 a little more--it sounds less analytical to me, but that's just personal preference. Both are very good amps. Funny thing is I own a 10 and do not own a DR amp, but that choice was made based on where the amp would be and I could not afford the heat generation of the DR.

oh and I have listened to the Classe 15. Still liked the SA220.

The new NAD S200 is an awesome Amp.

You don't mention your speakers, other gear or music preferences. Here's what I've heard...

The Marsh is a terrific amp and affordable too. It powered a friend's ML Ascents to excellent effect, a tonally accurate , musically realistic amp.

Another acquaintence has a Spectron Musician paired with Dunleavy IVs - very impressive when I heard it. More watts than the Marsh if your bass drivers require more power and damping. If you have electrical issues at your house, I've heard that digital amps can be sensitive to crud in the lines.

Your amp selection seems to lean to warmish amps...have you considered Bels???

Really, your speakers' power requirements plus your personal taste, other elctronics, room etc. all enter into the equation.