I used to work at Signature in AUS.....good group of people if they still have the same leads. I really enjoyed working there. Unfortunately the customers are all pissed off at being gouged on fuel at $5/gallon for LL and not much cheaper for Jet-A.
At least the frac pilots tip you well for lav service and aircraft cleaning. It gets incredibly busy on football weekends, and all the aircraft towing you do in hangars can be nerve racking (signature is in charge of all the municipal T-hangars).
The pay sucks (I think they start you off at something like $8.50/hr, with a 50 cent raise every 6 months or so, but there are usually opportunities for overtime shifts. The corporate politics and constant policy changes can be annoying, but overall I think it was good experience.