I've had no problems with Kwik fit near me in Bridgend. Regularly had my Zeds oil changed there as it only cost £39, and mot'd my banger there once, which passed no problem. Depends on the staff i suppose.
I take my cars to R J Davies in Pontypridd, (not far from Pontypandy were Fireman Sam lives ) for my MOT's as they are very reasonable, and will even fit you in out of hours, even on a sunday