My mate has a Chips away franchise & he's work is awesome!
I had real bad scrapes on the front & rear bumpers of my Evo (Red TME) & he got them sorted 100% - no one & I mean no one could tell the bumpers had been repaired & blown in
I think it's all down to how good the Chips away dude is, if he's rubbish then he's works going to be rubbish too.
I bet if you looked at the bumper a couple of years down the line it would have faded differently to the rest of the paint and give it away.
While I agree with you that the initial results are down to the individual guy doing its talents I also agree with the posts above that its basically just a quick and cheap way to tart up a car to flog it and is best regarded as temporary, especially on a red car, lol