Information Overload On Replacement Windows

My wife and I are in the process of accepting bids for window replacement and we had two additional companies come out for estimates today.
At this point we have received quotes on a handful of different windows from 4 different companies. We have one more appointment scheduled but I might add one or two more to the mix, as my research on windows has revealed another two brands of windows that I might want to use as a comparison.
The problem is that we are receiving so much information and each company/installer has their preferred product to pitch and we are trying to weed through the fluff to determine what is truly important. One thing that I am not fond of and we have had happen twice now is to have the salesmen/representative try to make a pressure sale on the spot. You can offer the best discount in the world but I am not going to rush into a purchase of this magnitude, sorry buddy!
I’m not looking forward to spending this much money on windows but I want to take the time to ensure we are getting the best value for our money. My wife on the other hand is ready to make the decision without doing all of the research and technical comparisons. She had a better *feeling* about one person that came out to give an estimate and said she would be happy using them, even though she couldn’t tell you the pros/cons of the window they proposed. In a situation like this, I tend to over-analyze all of the details and try to make the absolute best decision so I think we will need to come to some sort of compromise.
If any of you have experience with replacement windows (specifically vinyl windows) I would welcome any and all additional feedback and advice on brands and features to look for in a window. I’ve been reading a few online discussion boards and I’ve been able to find positive and negative information on just about each window we are considering. My next house is not going to have any windows!