i have always serviced my own brakes. i like to know they have been done properly ( you only get one life apparently unless you grow wings) so unless you have had a car from new you dont know its brake service history whilst changing pads over the years. anyone can stamp a service book after they have been skimped. even if you go to a reputable garage or quick fit type tyre/brakes centre you would not know any different. do these service guys remove the guide pins and clean them or wire brush the carriers and use brake cleaner ? not all are guilty but in most cases where pads are fitted quickly just do enough to get the old pads out and force the calliper piston back in to get in the new ones. so its little wonder eventually they stick or do not retract properly. brake fluid never changed ...brake hoses clamped ... the list goes on. we do all live in this just " turn the key" car age but lives can be thrown away just as easy as cars.....