My Gammill was also a used machine. I've had it for a year and I've not had any problems with it. I did get it from a dealer and they gave me a one year warranty on a 2004 machine. I do not have a stitch regulator either. I don't mind not having it but sometimes I think life might be easier if I had one. Maybe someday...
Good luck! I hope you find one you can't live without!