I've seen several posts on here about unusual amounts of CPU usage, but almost all those posts go something like:
"Hey sometimes sublime spikes"
"It indexes projects now"
"Oh ok, cool. Thanks!"
I've waited a while before posting this, and I'm quite certain this is a different issue. I don't know off the top of my head what information is going to be most valuable to you, so just ask me any questions you have, or any diagnostics you want me to report and I'll be happy to do it.
I'm on OSX Mountain Lion running ST3 build 3021.