Well I love share sheets, iCloud syncing, and AirPlay, personally. Gatekeeper is a great compromise between a fully locked down system and a fully vulnerable one. And the new Safari is the best Safari ever, as the saying goes. So I count 4.5 on my end.

Anyway, an OS is more than the sum of its newest features. On the whole, OS X 10.8 is a stable, polished, powerful, fully-featured operating system. There might not have been a big feature like Time Machine or Exposé in a couple versions, but I'd much rather use 10.8 than 10.5.