I worked for US Xpress for about six months. They have nice roomy trucks, which is handy because you'll spend a lot of time sitting still in them. Lots of long layovers and dispatchers who pay lip service to getting you home but can't seem to get the job done. I gave them over 30 days' notice that I needed to be home for my oldest son's birthday and they couldn't manage it. They'll tell you that you get every other weekend home but when you get there they'll tell you that since you were only on the road for 12 days instead of 14, you don't actually get a whole weekend.
Pay was fairly miserable just because you spend too much time sitting in truck stops waiting for your next load. It can be pretty expensive out here and two days eating truck stop food can hurt.
Personally, I wouldn't drive for them under any circumstances, but I also understand there are some people out there who think they're great. Good luck in your search!
I don't know anything about Transam other than seeing their yard in Olathe, KS whenever I pick up at Tyson.