The windows are fine -- the quality of the end product is adequate, though there was some damage to some of the window frames.
More importantly, the service was atrocious. The workers broke one of our windows, leading to a large amount of broken glass strewn all over the garden and porch. They only cleaned the mess after an angry phone call and further monitoring of their work, which took time out of our work day.
Furthermore, there was a terrible mess in each room they changed a window. Soil and leaves were strewn over one of the bedrooms, with small shards of glass found on the carpet. Items were knocked over negligently and not put back, and there was no attempt to cover or shield any valuables from damage.
For the money we spent, we would not recommend these guys to anyone else.