Conrad Johnson vs. McIntosh Tube Gear

Those amps are supposed to be very good. I owned V4's,
although I am sure they are different sounding than the
Triodes. The V4's were definitely on the warmer side. I
guess all I am thinking here is, have you tried a different
preamp. I am sure the Quickie line pre is good for the
money, but can easily be improved upon. Maybe try a Cary
or the Mc 2200. How about a used premier 16LS. I really
liked my Mk.1 version of that pre.

It is mainly a matter of taste. I am not sure any of us can really tell you what to do.

Is there one brand whose current gear's house sound is considered the most warm?

Are you running CD's or vinyl. With 96db speakers any noise or excess gain in the pre and power is going to come out, expecially with CD as the source.

I think that the cj prem 16 is one of the true great pre amps. better in most ways compared to the Mac C2200 which has poor bass drive and slightly lean upper mids and lower treble. However if you mate the prem16 with a cj power amp, you might have too much gain in the system and cj power amps can be a little noisy with 96db speakers.

Mac amps on the other hand are very quiet and you could afford either the MC275 or the MC2101.

OTOH, Quicksliver don't really have a reputation of being analytical thou.

I used to own an MC 275 and loved it (with a Cary preamp--maybe not the best pairing). Unfortunately it was stolen. I replaced it with a CJ 17LS/Premier 140 combination which is also excellent. My speakers are Joseph Audios (25si)so not that efficient, but either amp could drive inefficient speakers in medium sized rooms. Differences? The CJs have a better sense of space, depth especially and sound more classically tube-like. THe Mac had a wonderful sense of presence almost like an SET and better PRAT. Both amps have beautiful midranges though I'd opt for the Macs overall, especialy on voices, maybe just my opinion If you want a lusher sound maybe the CJ. Both are excellent amps. Overall the MC 275 is my favorite amp that I could ever actually afford. I miss it and hope the person who stole it rots...