I've posted Sweet16 2.3.1, the latest version of the Apple IIgs emulator for Mac OS X.
This version fixes the cosmetic bug in 2.3 that caused the speed display overlay not to stay in the corner of the video window where it belongs when you resized the video window.
Also, support for mouse wheels is improved; the vertical wheel is more reliable, and support for the horizontal wheel has been added. Be sure to install the updated SweetPrinter extension on your emulated IIgs to get the improved wheel support.