I have to use a new MacBook Pro at work (a mixed blessing). It has a virtual real ESC key. I find this really awkward when typing Actionscript and using autocomplete. I need a real key (for tactile feedback).
Try giving it some time. I'm on the new MBP too and use autocomplete constantly. At first it was a bit awkward but after a few days it feels natural. Now actually pressing ESC on other laptops feels awkward :D