I have a U5 and absolutely love it. i use it with upright and electric, and to my surprise, i rarely touch tmhe eq with either. i've ade a bunch of postings about the U5. It's pretty remarkable., You get very rich, deep, warm lows,but the rest of theraneg is really present, without any obvious deficiencies. on most amps, i was always cutting the treble or boosting some frequency range, and i still heard soem unpleasant artifacts in the tone, The U5 just flat sounds good--more musical, more usable.
ProkenKlang, who loves the most expensive gear possible, says the millenia unit "smokes" the U5. Maybe a little clarity? "Smokes" doesn't tell me much about sound, neither does "kills" or "blows the doors off" or any of those phrases. Maybe, prock, you could explain what "smokes" means?
The attraction of the U5, for me, is partly that it's relatively cheap--it has a great tone--better, to my ears than boutique preamps like the Aguil;ar or the demeter--but i got mine for $418 on ebay. Expensive for a DI, but what you're paying for is simplictiy and a focus on sound rather than features.
The Millenia TD_1 is I think like $1800 bucks, no? I would love to try one, it looks really great, but i wonder if it's really nearly four times as good as the Avalon? maybe--if I had a lot of dough, I'd jump on the Millenia to find out. Manwhule, the avalon is bette than anything I've ever played through except maybe a neve studio strip.
I drag the avalon to bar and club gigs, no problem.