We bought 5 double-glazed windows and two sets of uPVC patio doors. Two of the windows have an appalling finish that I'll have to remedy myself (scrape away the silicone that is all over them and re-apply). The window fitters returned three times to resolve the issues with the doors and they still haven't fixed the problems. The locking mechanism on one door was manufactured incorrectly, the other is exceptionally difficult for a man to close and impossible for a woman. The fitters stated "It'll wear in". Obviously they don't know what they're doing!
I will never buy anything from this company again all they have done is come up with excuses for poor workmanship.