Hi Dev, I know what you mean. This is why I drive a Mercedes 12 cylinder, a Bentley and an old Rolls Royce. They drive more relaxful at lower speeds, you dont hear them, yet you know: if you need power, it is simply there, silent and mightyful. Its the same with big tube amps. I dont need them due to playing at maximum levels all day long, I want them because the low/mid levels sound so great, they dont mean any effort to such systems. Interesting that you once prefered the Ref3 over the Ref5.
I never heard the Ref3 (because everybody says the Ref5 is better anyway). I just can say that the complete sound "image" differs enormously between the Ref2 and the Ref5: when I heard the Ref5 the first time (it already had 300 hours on the tubes, so reasonably burned in, no excuse there) I was close to being disappointed. The sound quality was excellent, but the Ref2 was much more direct, wormer, unbalanced in a nice way. And the Ref2 has a bit more bass level at the lowest end. Having "corrected" the bass level (by adjusting the subwoofers differently) I concentrated on the mere sound differences. The Ref5 is much more precise, first impression is a bit analytical (as far as this can go with a tube preamp). The soundstage is wider and deeper and seems to be a bit more away from my listening position. It is more neutral, better balanced (in terms of voice vs instruments). The voices and instruments are a bit clearer, everyting seems to be better "seperated", less "mixed up". But it does not miss the ARC/tube sound as well. Once getting used to the Ref5 sound, the Ref2 sounds less clearer, the bass too whoppy, and the whole sound picture unbalanced (more bass, voice determines more) and somehow more "mixed up".
But I am not sure if the Ref5 would always win against the Ref2 if someone has only limited time and can only do a short comparison. The Ref2 is easier to adopt when hearing it the first time (especially when upgrading).
Anyway, I am now adict to the Ref5, so the preamp decision is done. The issue with the power amps is simply that is it much less practical to test them at home, simply because the transportation is a project by its own. Also switchin from one amp to another one is an issue of cable lengthm stand position,... With a 13kg/27lbs preamp that
is easy... I usually try to have components fro ARC that are from the same "generation", so I would prefer the 210s for that reason to the 300/600. They also have fewer tubes, need less input power,... Nevertheless the 610 still might be an intersting option. I will try to find an opportunity to compare them one to one (even if is not in MY listening environment, but at least it should be the SAME for amps). Thanks for all your inputs! Enjoy the music!!