Pass Then vs. Pass Now

Hi 'Goners. 

Long time lurker, first time poster hoping to receive some wisdom from the community. Thinking about an upgrade (aren't we all?) Currently powering Devore Gibbon 3xl with a Rogue Audio Sphinx v3 and am inclined to try out some class A solid state amplification. I was a long time happy owner of a little Adcom GFA535. (I bought it in college in '88 and just let go of it two years ago!) That got me interested in trying out another Pass design. I have been weighing a Threshold400A vs. an XA30.8

Anyone have experience with Devore Gibbons and either of those amps, or thoughts on whether the newer PASS is worth triple the going price of the vintage  piece?

Open to any other suggestions on where to go from here with the system as well. For discussion, I  live in an apartment and use it almost exclusively for vinyl. I am a musical omnivore. The front end is a Clearaudio Performance DC with Tracer tonearm and Hana SL running through a Pro-Ject Tube Box DS2. If I upgrade the amp I plan to continue to use the tube pre in the Rogue Audio integrated, for now. 

Thank you in advance for your input. Your time is much appreciated.

Shawn