Spaz,
1st, I love the moniker. That is how I feel about my usual approach to equipment "upgrades" and auditions.
I too have a Pass Labs amp, the X250.5. I recently sold a BAT Vk5i preamp, used it with a Cary SLP 05, and for a long time an ARC LS15. All of these are tube preamps and represent a great deal of variation on implementation of different tube types. All had +/- 's. All, from what I heard, happen to be in the cool neutral group. I never heard a CJ preamp, from what I read falls in the romantic, classic tube sound, I guess depending on vintage.
I can tell you that despite all of these preamps being pretty solid offerings, none really made me feel "at home" with the sound long term. I felt like the presentation was a bit pushed too far forward as if the system was trying to hard to get me to listen to the vocals and other aspects of the upper midrange. I think the Pass amp has very nice qualities (on its own) and has such an open midband that the use of tube preamps that seem to "enhance" the midband may actually do more long term harm than good. I am patiently awaiting a Pass Labs X2.5 solid state preamp, should be here early next week. Though this sits at the "entry" point for the Pass preamp lineup, at $4k retail and since it's based on the same supersymmetry gain stage as the X.5 amps (that I love), I am pretty sure it will be a complementary approach to source/volume control. I am not expecting big fat tube glow and all that, in fact i'm hoping it is not that. On some recordings that "spotlit" midband can actually be annoying. Who knows? Given that i've been listening to tubes the past 3 years it will be an interesting thing to see if an all solid state amplification chain will do it for me. I love the amp, and I have a hunch that if the x2.5 is as transparent as the amp I should be pretty happy with the result...