What Mr. Pip said: The Blue Ridge Parkway, at least the portions in and around Maggie Valley can indeed be navigated at speeds well above those posted. And it ain't no interstate. So if you want to use it to get from one place to another, do so with the idea that you are not in a hurry, and want to enjoy the gorgeous views and countryside. Kinda like: do I take the I5 or the PCH? Depends on what it is you want to do. And how much time you have to do it.
PS, have done the PCH top to bottom a couple of times, and I'll put it at #1. Skyline drive and BR Pkwy are very nice, and may be the coolest thing in the East, but you just cant beat the PCH. IMHO.