Hey Sam. I did not realize this was your thread. Congratulations on your purchase of the 27.5! A very smart move! Isn't it strange that such an old amp like the 27.5 beats out most of the current high end stuff? Are you keeping the VK-55? The VK-55 is better than all amps that I've listed but I believe the 27.5 is better than the VK-55 overall. However, I think the VK-55 has more bloom in the lower midrange...great for female voices. Yes, you are right about the Pass. It is initially impressive but does not hold up in the long run due to it's brightness and hardness.
Hopefully you will keep both amps, they are both great amps.