I agree completely. My company's site was set up with yui2 before I came on board. Maintaining that old code and being forced to write new features with yui has not been a pleasant experience. I am transitioning the site to jquery as soon as possible. I've looked at yui3 over the last few months and while it's better than 2, it's still a mess to work with. There's also performance issues. Jquery is simply more capable and more efficient than yui3 according to recent benchmarks