3D transforms are hardware-accelerated on iOS, so all you have to do is use the 3D syntax whenever you're doing it, and it performs great - at least on 3GS and above. Most performance problems on iPad are from people trying to do memory intensive stuff that causes the iPad to crap out. On the iPad you only have a tiny amount of memory to work with in web apps - iPad2 is MUCH better for everything web related. (But you should post your offending example for people to take a look at. You could be doing something simple wrong.)

3D transforms are hardware-accelerated on iOS, so all you have to do is use the 3D syntax whenever you're doing it, and it performs great - at least on 3GS and above.

But you are not using transforms in your example, you are using a transition on position, which is completely different, and yes - results in crappy fps on mobile.

Instead, you should be using -webkit-transform: translate3d(-100%,0,0) (or a suitable analog). You can see how much smoother this is from the example in this page.