Thanks all... Peterayer - Husk01 was referring to a posting on What's Best Forum as well.
Yes, I own the Q5's. No time for the pre/amp selection. Seems Alon Wolf has paired them with Soulution, Spectral, Boulder and VAC, so that's kind of how I'm trying to home in on the short list.
I've heard them at my friend Husk01's home with a Gryphone Collosseum/VAC MK2a and they sounded great, but I didn't have enough time to make a judgement.
I heard them with the ARC REF 250/VAC MK2a and didn't care for that at all. Then I heard them with the Soulution 710/VAC MK2a and that was much more to my liking, but I still felt something was missing - maybe they need more power...
Interestingly, the VAC pre was common in all auditions - I do think the Q5's benefit from some softening/warmth in the pre section. Other than the REF 250's, I haven't heard them with tube amps... I ended up steering away from tubes after that audition.
I've been told the Spectral offers a more "full" and "special" sound with a bit more extension in the low end than than the Soulution.
I'd be keenly interested in feedback if anyone has conducted an A/B comparison in the same room with the Q5's between the Soulution 710 and Spectral 360SII - or - between the Boulder and Spectral.
Thanks again all - good feedback.