I am also in the process of replacing the windows in my house. What I decided to install were exterior vinyl clad windows with exposed wood on the interior. Most vinyl windows that I have seen the support around the glass is a lot larger than on wood (I am sure there are exceptions, but I wasnt finding them). Second factor in the descision was that we like the look of natural wood more. The third factor that I took into account is there are some reports that vinyl expands and contracts at a different rate than glass so there MIGHT be a failure at the connections(in my case I would be the person out on the scaffolding if it fails), so either way check on warranty. Also if someone else is installing, get references, addresses, and go look at the jobs and see if the windows look like they belong there.