3 choices for power amp

my recommendation is the same as vinyl valet stick with the amp within your family I think it'll probably sound the best.

I've owned the Benchmark and currently own the Atma-Sphere Class D.   I personally think they sound pretty different.   

I found the AHB2 to be extremely clean sounding, very solid bass, and highly resolving.   It had a super black background and you could hear into the recording like crazy.   I also found it to be a little lean sounding and 2 dimensional, not much front to back soundstage.   I liked it but at the time had a Pass X250.8 and preferred the big Pass amp.   The AtmaSphere has the super black background and solid bass, but sounds much more like the Pass to me.   I don't think it is as resolving as the AHB2 but it has more the color/tone of the Pass with better side to side and front to back imaging compared to the Benchmark.   To me, the AHB2 is a great tool to analyze a recording, where the Pass and AtmaSphere bring you closer to the music/soul of the recording.     My preamp is the SimAudio 740P (used on all 3 amps).   I would go with the AtmaSphere if you have the AtmaSphere preamp and am happy with the AtmaSphere sound signature.

Cheers

+1 @vinylvalet   The Coda is very special!

I know this sounds out in left field. Galleon A75. Down the road you will understand. 
At $1500 you are getting 95% of those including CODA but at 25% of the cost. 
good luck! 

@hsounds Have you auditioned the Coda S5.5 along with the Galleon A75 with your speakers in your room, level matched, etc? Or any Coda amp?