Swings and roundabouts. Ours were done by Safestyle 25 years ago,11 windows, 2 doors, all fitted in one day. The doors were replaced a couple years ago and tbf, one window doesn't seal as it should but 25 years is pretty good going in my book.
The pricing tactics are stupid though, starting at silly prices and you have to whittle it down to suit your budget, it's a bit of a silly game. There again, ours started at stupid money but eventually cost less that £3k...but maybe the quality falls as the price does, maybe the stupid prices quoted at first would have given much better locks and materials.