Used PS Audio BHK 300 monoblock or (2) new benchmark ahb2 bridged?

I've never heard the Benchmark amps but I own a pair of the PS Audio BHK 300's.  I bought them after hearing a friend's Magnepan 3.7s being driven by the D'Agostino S350 amplifier and marveling at how much better his 3.7s sounded than mine.  I can't afford the S350 so I put a search up on Hifishark for the BHK 300's, Pass X350s and Bryston 7Bs.  The BHK 300's were the first that came up at a price I was comfortable with.  I really didn't know what to expect.  I have owned the PS Audio M700 and S300 before and didn't really like those class D amps so I was concerned I might not like the BHK 300s but it turns out they are simply marvelous.  I have used them with Magnepan 3.7s, 20.7s (my current speakers), and Tekton Moabs.  The biggest surprise to me was the fact the BHK 300s sounded better with the Moabs than either the 300B or 2A3 tubes amps that were my favorites before and that had beat out a variety of other solid state and tube amps.  But the BHK 300s really make the Magnepan speakers sing.  Frankly, I can't imagine being unhappy with the BHK 300s at the used pricing.