I haven't heard anything positive. Have talked to two guys one in STL the other in DFW.
Both told me pay is low, you don't get paid extra for working on days off or doubles unless you meet some certain criteria, I believe over a 3 month period. I believe they also said you have no set days off, they can change every week.
Needless to say they both were leaving. I have heard the DFW facility is waaaaaay short on staff.