I will add this. Usually when a company offers a high end window, they are much more likely to do a good install. If they care enough to use a good product, they usally care about other things as well ( install, service , ect). The higher end vinyl offerings are not only more costly but a high end manufacturer will drop a dealer rather quickly if they get a lot of install related complaints.
Ive seen it happen.
For all those Replacement Window questions