I use Tonex, NAM, Tonocracy, and sometimes TH-U. Still kinda like the UA guitar amps at times, so I'm not sure I'd say "awful" haha. Fuchs Train, Buxom Betty, and Fender all have a place for me. I can find pretty awful captures in any of the aforementioned, and I can find some hideous amp sims from any company you want to name.
As far as "big" guitars, I'd have to hear a reference for what you're trying to achieve, because most of that is in the mix for me. I'm sure a lot of it is genre dependent, but I'm mostly doing clean/edge of breakup. Double tracking and basic mix techniques can go a long way. Now if it's some ZZ Top-type track with guitars front and center, I'm not sure I'd reach for UA amp sims, but like someone said above, just some preamps and channelstrips can get you a pretty vibe'y sound. Also, I'm basically recording a dry track for anything I record anyway so I can re-amp depending on where something needs to fit.