I’ve only ever had great service from KF. I’ve had a few services there on a car and there were no problems and it was cheaper.
I’ve had the “sorry can’t repair that” on tyres and have been shown why and have no complaints.
Considering the mass nature of the business, the number of complete tools out there that will happily drive on slicks or drive an older car and refuse/don’t plan for or don’t expect big bills, it’s not suprising there are horror stories.
A local main dealership, on a 3 year old car, messed up a service and forgot to put oil / enough oil in. The mgmt light came on after a few miles, pulled over, checked the dip stick and it was bone dry.