I upgraded SL -> Mavericks a few months ago when it stopped receiving security updates.

It's slightly worse (I don't like mission control, messages is useless to me) but not as bad as Lion (i.e. you'll just need to disable the stupid scroll behaviour, but performance is good).

On the plus side, you get the option to use new software developed for "10.7+" (heroku's db client, atom editor, swift etc)