+1 to Mike's comments. The Simonton is not worth consideration in that company, IMO. The Okna is easily the best choice of the group. If you don't need the frills, the 500 is a great choice... That really is some aggressive pricing on the Softlite products though. How do you feel about the installation companies? The price premium could easily be made up if you're dealing with a company that will deliver superior quality and service, but if they are about equal, it would be difficult to justify that difference on product alone. If I were you, I'd let the Okna dealer know the situation, and see what he can do for you on the 500 pricing.