Thank you so much for your interest in and support of the GreenSock Animation Platform.
I haven't created a single line of the platform's source code, but I know enough to tell you that a college-level course could be written trying to answer that question. TweenLite and its siblings have been battle-tested and refined for nearly a decade. One of GreenSock's core values is that our tools not only work, but they work well under stress. Optimization and performance are just as important as the features themselves. 1000s of hours of testing and optimizing have happened on the ActionScript side of the fence which allowed the JS version to come into existence which such amazing performance and features out of the gates.
Jack answered a similar question recently like so: http://forums.greens...tion#entry22883
It really isn't part of our DNA to tear down other products and explain what may or may not be wrong with them. As far as jQuery goes, both Jack and I will tell you that we have tremendous respect for jQuery. jQuery is simply an amazing tool that takes so much headache out of cross-browser web development. Using jQuery as a selector engine with GSAP is a wonderful way to develop and one that we hope many folks will embrace. Personally, I'd be lost without it.
Although you may not get the comprehensive answer you were looking for right here or now. I urge you to read and participate in these forums often. Every day some little nugget of info is going to cross your radar that you wouldn't get from just reading about and using the features that you need. Over time you will not only learn of the many things GSAP can do but you will get a much better understanding of how it all comes together.
Thanks again for your inquiry and enthusiasm.
As you continue on your voyage with GSAP, please don't hesitate to ask if you need any assistance with understanding how certain tools/features are supposed to work.