That's roughly what I'm running + some Adobe CC apps and a half-dozen Chrome windows. I believe the difference is the cached v. uncached performance of Mission

That's roughly what I'm running + some Adobe CC apps and a half-dozen Chrome windows. I believe the difference is the cached v. uncached performance of Mission Control; after the initial (really really long) loading time it's fine, but once enough windows need to be re-rendered it freezes up.