My 81 240D is framed. My 82 300CD is frameless. Even with a window misalignment, I have never noted real wind issues with the 300CD (wind, versus road noise seems to be the issue).
Now my 135i is a convertible, so has frameless windows. They seal well and dont leak air, but because the top has some give to it versus a hardtop, I do get an ocasional squeak on really bad roads. But that probably means that I need to lube it more than anything.
Ive heard that frameless is louder. Practically speaking, I cant say that Ive noticed it.