Audio Research REF 75 vs VAC Phi 200

I don't think you can go wrong with either of these amps. I personally like Vac equipment a lot and have found that Kevin Hayes of Vac is a really great guy to deal with.
Alan

Vac is a much better amp!!

I have no view as to which amp is better. I would caution you though that the amps may have different electrical attributes that may affect speaker compatibility. Specifically, output impedance, damping factor, and power supply size. If possible, try to audition the amps with your speakers.

The AR has very few rolling opportunities with the KT120s and 6h30s, pretty much stuck with very few choices unlike the VAC.
One positive, I could drive the AR to manufacturer for service.