Weird, for me it was kind of mixed. In the bedrooms facing the street, noise dropped noticeably, but in our kitchen area facing the backyard... honest...

Couldn't agree more on this point. I've seen neighbors spend a fortune on top-tier windows only to have drafts and leaks because the installers rushed...

I've had vinyl windows for about 8 years now, and overall they've been pretty solid, even in humid summers. But I had a similar issue with one window ...