The only first-hand experience with a neoprene gasket I have, is with the neck-gasket on my Bpod. It's probably different, but I must say, it has kept me very dry. I even did a bath-tub test when I first got it; I plugged the holes with tuppleware, and submerged it; it came out completely dry on the inside.
There's only so much a company can do for you. For routine maintenance, like re-proofing your suit, you can easily do it yourself faster, and possibly cheaper. For gasket replacement and the like, you can always take it to a local shop for repair.
Not sure if I'll be able to replace the neck-gasket easily when the time comes. Not sure how long it'll last, but if worst comes to worst, I could always get a rubber neck-gasket for it. I will say, I have had no leaks. So if the neoprene gasket is done right on the Nookie Zone, it will work just as well as a latex one.