I have problems with poor scrolling performance in iOS6 UIWebView component..In iOS5 scrolling was really fluid, though. So I have searched the web little bit and found this (part of iOS6 beta changelog).
WebKit no longer always creates hardware-accelerated layers for elements with the -webkit-transform: preserve-3d option. Authors should stop using this option as a way to get hardware acceleration.
That could be the reason, since the html site my app displays uses lots of css3 transformations.. Please have anyone a solution or advice how to force webview switch back to accelerated rendering model?
UIWebView still does hardware acceleration if you use a 3D transform (e.g. -webkit-transform: translateZ(0)). It just no longer does if you only use -webkit-transform-style: preserve-3d.
If you have an example that is doing 3D transforms, but got slower with iOS 6, you should report it at Apple's Bug Reporter.