Okay so when I eventually DO get my Line6 POD X3 Pro, I need a power amp to pair with it. I'm looking for a good, cheap, tube power amp (or a solid-state power amp that can give a good tube amp sound/sag/feel). Looking for a stereo amp with around 50/60 watts per channel at least, any suggestions?
Also, while we're on the subject...when people talk about prefering the sound/feel of tube amps, is the bigger contributing factor to that the preamp tubes or the power tubes? I know I prefer tube amps, I just dunno why or for what reason I prefer them more.
My suggestion is the Mesa 2:50. It's stereo and 50 watts per side, and the great thing is that it has a bias switch so you can run either 6L6 or EL34 tubes, depending on whether you prefer a Mesa or Marshall type sound. After my little birthday spree today, I now have two power amps, a Mesa 50/50 (the predecessor to the 2:50; runs 6L6 only), and now a Peavey Classic 50/50, which uses EL84 tubes and is closer to a Marshall sound.
One of my configurations is to run a power amp and iso cab in the fx loop of my Axe-FX in place of the cabinet sims, and now I can do quite realistic Mesa and Marshall sounds since I can switch between the two preamps. It actually has me rethinking whether to use analog preamps at all, since the Axe-FX is an all-in-one solution and sounds great with a real tube power amp and speakers once you figure out how to set it right. I suspect a PODx3 Pro would do well, too.
As to your second question, they're both important in getting a great sound. However, power amp tubes, to me, make the biggest difference in getting a rich, complex sound. You can run solid state preamps like Rocktron through a good tube amp and still sound great; I don't think the reverse is necessarily true, since tube preamps can sound fuzzy and unfocused without a good power amp behind them.