slow is frustrating no doubt, but as long as you don't have to go back because they forgot to tighten a clamp or something stupid because they were in a hurry or trying to impress you....
I'd rather pay more to have a job done right than the opposite.I have often noticed the shops that I have had bad work done at were unkept, no organization, tools laying everywhere.To me, sloppy shop=sloppy work.If a shop takes the extra time to go the extra mile to keep his shop neat and clean, things put away properly, than the work usually follows suit as well.
There is a shop in Nashville, TAFA, (Truck Axle Frame Alignment)That is like this.You can eat off of the floor.Literally.They even wipe off their tools, and the truck lifts.The whole thing.Their reputation is unheard of.They've been in business for over 60 years.They are not cheap, by any means.And you're truck will not leave the shop until the job is done right. They do not have customers coming back to have job corrected.Their customer list and base is nationwide, out of that one shop.They take pride in their work, never in a hurry.