Actually I find that modern tube amps are only ever so slightly warm, and even this is highly dependent on tube choices. My Singlepower Extreme, for example, with some tube combos, was LESS warm than the SS Meier Opera. I do prefer just a touch of midrange lushness, and as such I tend to choose tubes that offer this. I stop way short of syrupy, though.
Some SS amps are way to bright sounding to me, but many, like the Opera, the Purity Audio KICAS Caliente, are actually themselves ever so slightly warm of neutral. What i have never heard, though, is a SS amp that can truly deliver the kind of midrange sweetness that sounds "real" to me. Only good tube amps seem to get this done, for me.