I actually find the built-in Xcode documentation (⌘⌥?) reasonably snappy (and I'm on a pretty slow Core i3 box whose only redeeming feature is 16GB of RAM). I

I actually find the built-in Xcode documentation (⌘⌥?) reasonably snappy (and I'm on a pretty slow Core i3 box whose only redeeming feature is 16GB of RAM). I would definitely choose Google (or your app -- it's pretty slick) over the current documentation web site.