Nothing but a poor experience, they couldn't care less about customer service or about treating the customer with respect. In our situation every single window and door had to be reset, every window & door had air leaking past the badly adjusted frames. They also attempted to get us to sign off the work before it was complete a number of times. We were spun a number of different lines about the air leaks, the best and most disturbing by far was where the fitter said "oh yes that happens, sometimes the frame needs to settle" - In this case it was the fact that the frame was not square and had to be "adjusted" by almost 25rmm and that the window opener was incorrectly adjusted It wasn't even down to a particular fitter, we had more than one team and they all made mistakes that i would have expected only if they were amateurs. They "lost" a complete window, i'd have given them more props if they had just said "i'm sorry it was forgotten on the build list and we have to rush it through the factory" but they didn't and it took 6 weeks to appear. Other than asking to get paid their ability to communicate is shocking, overall an horrendous experience that i'd rather never repeat.