I meant that I was comfortable with either other the sales locations and installers. I have talked to several people I know who have had windows installed by the installers out of the location I am going to and they have had nothing but positive to say. I am unsure of the merchandise and what’s the better deal.
The real question is: what qualifications do the people that you know have to make that assessment? Sure the windows probably look and function nicer than the old ones did, however, for all they know, they could be leaking water into the walls due to improper installation and then after 10 years of service-call and warranty-claim filled years, maybe they will be ready for the dump.... That's not to say that it IS the case, but how would you or your friends know whether it is or is not. When shopping for windows, your goal is to mitigate the chances of future problems, and end up with a quality product and install at a fair price... You choose a quality product based on the objective thermal and structural performance ratings, with consideration given to the manufacturer's history and reputation for quality. You choose an install company based also on the history and reputation, as well as knowledge of proper installation techniques, professional service, perceived trustworthiness, etc.
Given those parameters, I believe that you would be doing yourself a disservice if you don't at least take a look at another option or two, particularly one that would rank well in all of those areas. There are companies running around that gouge (IMO) on the price of a vinyl window ($1000+ea), however in the end, you would still be far better off overpaying for quality than buying a low-grade product because it is cheap. That said, if you do your due diligence in this process, you should be able to find a great product and installation for a good price, perhaps in the same range as your existing quotes.