Sorry, by "Arduino 2" I mean the Arduino beta IDE.
The actual hardware I'm using is an Arduino Nano, so ATMega328P. This is for a project where I'll be producing my own PCBs with ATMega328's on them, so the final thing won't be on a standard Arduino.
I'd rather avoid changing chips at this point. While I could move up to ATmega1284P's for the much larger RAM, I'd rather optimize things within the 2K limit as the bigger chips are also much more expensive and the final project will involve at least a dozen of the modules I'm working on.