[weeksie]

Perhaps it's tabbar-mode but for some reason I find Aquamacs to be crazy-slow when compared to the vanilla Emacs.app. I realise there's a lot of extras that are included in Aquamacs but the difference is just insane. It's a shame though because I love the default setup (after I've turned off all of their modifier key changes).

[GeoffWozniak]

Same here. It has consistently gotten slower since the 0.9+ days. My simple test involves loading up Slime, opening a Lisp source file of moderate size and holding down C-n. The recent releases of Aquamacs consistently spikes at 25-50% CPU usage on my MBP. The lag is noticeable while editing.

[jz]

This has been my experience too. I'm downloading now to see if performance has improved.