Even something simple like www.google.com serves from 5 different DNS names. I have seen as high as 50. It is surprisingly snappier. Especially on older browsers that would only have 2 connections at a time open. It adds up faster than you would intuitively think. I used to have local resolvers that would mess with the TTL. But that was more trouble than it was worth. But it also gave a decent speedup. Was it 'worth' doing. Well it was kinda fun to mess with, I guess.