I like that vamps are horrible looking. They're supposed to be, they're the accursed undead. They *should* be so appalling that people think very hard about whether they want to tolerate that for the advantages or not. It's not like just joining a guild, it's becoming a bloodsucking monster. When I get tired of my Dunmer (for whom I chose the darkest black skin to make him look as "drowy" as possible) being a pale gray, I will have him miraculously cured and play him without the vamp stuff again. I'm cool with him looking gross as long as he has to act gross, it's fitting.
I think they should bring back the sets and being a vampire as multipliers for stealth.
After all, if you are willing to use 5 armour slots, stealth at walking speed. If you're willing to throw 10 slots at your stealth, you should get running speed with stealth.
And finally, if you're willing to give up 10 slots and become a creature of the night, you should be able to sneak as fast as a horse can run. Heck vampires are supposed to be super fast and super stealthy.
If you are willing to optimise that heavily for stealth, so be it.