Quandary

@rvpiano amplifier is one of the most impactful components in the system and introducing a different amp is a major change. Your system is tuned to the sound you like with the benchmark in your system. That includes all of your cabling. New amp is rarely a plug and play type of component.
You have to be able to hear the potential and commit to making additional changes if you change your amp, including cables and even a preamp. Ultimately it boils down to personal preference. If you don’t miss pass amp when it’s gone, then it’s not for you. 

Sounds like you got a lot of experience for your experiment. The conclusion that comes to my mind is that a major factor in your enjoyment is detail… that is what Benchmark is about… hence a really good choice for you. The Pass and especially  CJ are about carefully walking the line to balance detail, midrange bloom to capture the perspective of music in its venue . Anyway, hopefully you are happy with the experiment. It would have been worth it for me. 

Someday, if possible, try to audition the Benchmark preamp with your system. Not counting the difference in sound, which is still the most important, but only you can tell, the volume adjustment of 1/2 db on the remote will allow you a lot of precision.

With the Benchmark I can set the volume control knob anywhere between 11:00 and 2:00, a much wider range than any of the other amps. The CJ tube preamp has been refitted with Teflon caps and is an ideal match for the Benchmark.
The combination of solid state and tubes works.  The amount of detail, warmth and soundstaging is impressive.

Yes, tube linestages can work well and sound good with solid state amps.  But, the biggest difference in sound comes from using a good tube amp.  I hang out at a very serious audio shop that does not sell ANY solid state amplification.  They also don’t sell high powered tube amps.  So many visitors to the shop are utterly amazed at the sound; for some, it is like a religious experience.  They have never heard this kind of sound at shops pushing solid state and high power tube amps.
 

It is all about the sound.  As good as a hybrid tube/solid state sounds, I don’t think one gets close to the full measure of tube sound without a tube amp.  I’ve used solid state linestages with tube amps, and I prefer that combination to tube linestage feeding solid state.