constant force vs block and tackle

How much of a difference in quality is there between the block&tackle vs constant force balance systems? I have read that the constant force is a better system but not sure if it would make that much of a difference in a single hung window which will not be constantly opened and closed during the year.Thanks

No difference. Constant Force will say the are better and Block and Tackle will say they are better. Both are just fine. Block and Tackle is less subject debris than the Constant Force is but both are are going to serve you well.

One more question before placing order on the windows. I have opening which is 72" wide and will need two windows mulled and have read that they will mull the two windows at factory, but am not sure of any problems with the seal when transported.I know they can also be mulled in the field and just wondering which would be the best way to do it? Thanks again for the help.

If you go with a PGT, they use an Aluminum mull bar. You should have not problems and I actually would recommend it if you can.

So I should have the two windows mulled at the factory correct?

Yes.

I agree, factory mulling is better. It will have a metal bracket/fasteners in addition to the vinyl strips. On a field mull you'll usually just get the vinyl strips unless you get an ambitious installer.

Thank you both for the quick response to my questions. I have an installer coming tomorrow to be sure on what windows I can order.As three are set about 4 inches into the opening and three are flush with the stucco. Thanks