Get both contractors to give a reference.
If you really want to learn about who is going to do your home, then ask for a reference from a homeowner where the job do NOT go right and what the contractor did for the client.
Everybody is human and all contractors have made a mistake or two.

I agree that if you are only comparing the window, you are only getting a partial picture of the potential job.

That being said, the ThermalWeld is the superior window in my opinion and I have used both.

Thank you . The contractor has a 4.5 star rating form BBB and we felt comfortable with his presentation. Even though he used the normal sales technique, buy it now before the sale is over with at the end of the month.

Nothing wrong with incentivizing the sales process a bit as long as the discounts are not outlandish and insulting.

Every retailer of goods does the same thing.

I agree, there is nothing wrong with a " sales pitch" and providing incentives.