I just got home from ORD-SFO-SAT-ORD. I could have had three direct flights, but did ORD-SFO, SFO-DEN-SAT, SAT-DEN-ORD just to stay away from 3+ hour flights on RJs (ok, the extra segments and miles were ok, too). I'll tolerate them for short haul (up to 90 minutes), but no longer. And it seems like everything to Texas out of ORD is going UX.
I'm also finding that roller coaster rides on the RJ fleet will make me motion sick -- and that has never happened on mainline.
The E-170 isn't bad, but it doesn't seem like I can get them enough on my routes, so I stick with mainline.
It also seems like UX is much more likely to strand you when there are irreg ops, so I stick to mainline whenever possible.
And I was real happy to score 9J on UA 256 tonight. That is my new favorite seat