Does your sales representative throw around terms and not define them for you?
Do they tell you everything, but write down very little?
Do they start out extremely high priced, but suddenly 'save' you 30, 40, or 50% if you sign tonight?
These are all sales tactics that companies use to 'close' the sale that night.
One of the best things you can do is to see at least three people and kick every one of us out after the appointment. Only then will you be able to put all 3 quotes side by side and compare them. One might be higher priced, but have better performance. One might be less expensive, but they have a poor history of customer service. One might have done three neighbors in your area, but after you called them, none were happy.
If you decide that night, you are trusting the sales representatives word that 'everything will be fine'
DON'T! - We are not all Liars, but some of us are!
A good sales rep. should answer your questions and provide choices and options. They should give you at least 200+ references that you can call and talk to. (Not just 3 - 2 friends and their Great Aunt Millie!) They should sell a wide range of products for you to choose from, not just vinyl, or just fiberglass, or just composite windows. They should explain thouroughly their guarantee, or worse yet, their warranty. A BBB report should be given to you for your examination and log on to see if they have an A+ or an F. The length of time they have been in business is crucial. Ten years or more is the minimum, but longer is prefered so they will 'be there' if you ever have a service. All of these things can be found out on their BBB report. Check the company out to make sure they have a showroom. Some companies work 'out of their house' and can be gone tomorrow.
Then the most important thing ... Make us leave!
You will find with a little time and research on your part a clear winner will always emerge. You have probably lived with your windows for a few years, a couple more days should not be that big of a deal. You will be much more comfortable with your choice and not feel any pressure to go with any one company.
And then enjoy your new windows and/or siding!