I have never used their installers because the total price is half if you just get the windows yourself! I have bought the cheapy vinyl windows they carry and some Andersens and the staff have been very accomodating and helpful. I installed them myself and had no product issues EXCEPT the cheapy vinyl casement window cranks are not good and easily loose their grip. When the windows are not only installed properly, but measured properly, they are very airtight and operate well, without any issue of the tilt-in windows popping down and smashing on your head (this is a result of not shimming properly when installing). If you're not handy, you might be better off buying the product directly from WW yourself and then using a trusted handyman/carpenter to install them. All they require is a level, some wood shims, some screws to attach them into the jamb, and plenty of caulk around the edge. It sounds like WW's contracters are the real bottom-of-the-barrel and WW is hoping to make a little money off of the installation while keeping the overall price cheap to the customer--not so easy in this economy.
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