more speed is always good, filesize I would have a little more flexibility on. Tough call. I use TweenLite & TweenMax because they are lightweight and efficient I'd hate to give up any of that - they're perfect just as they are.
The real question is: Will goASAP take off - if it becomes real popular or a de facto standard then yes, I would want the option to use TweenMax as my tweening engine.
I'm going with a NO vote, with qualifications.
BTW, I couldn't find any licensing info on the goasap site, licensing is a huge issue for me.