From the testimonies on this Forum its an overwhelming DO NOTuse Re-Bath. We have stories of 5/8" gaps, poor caulking, overcharging and on and on. This family absolutly abhors Re-Bath. From my personal experience, we had our tub refinshed, had a 5 year warranty, they had to come back every year for 7 years, then we quit calling them and put a bath mat in.
Changing the tub is not an option in our case either because it is a big, heavy, cast-iron tub with beautiful ceramic tile surrounding it. The only way to remove it is with a sledge hammer; break it in little pieces and carry them out. Then you have to face the reinstall and repairing the 50's era ceramic tile.
I don't want to sound like this is a hopeless situation but, in our case, we gave up on it.