If the differences between css3 and no-css3 is so small as in this test (a few rounded corners, some drop shadows and some tiny gradients), you should totally go with pure css3 since it'll get easier to maintain but still look decent in old browsers. If you're having heavy artwork which will have huge impact on the experience; go with images (perhaps a mix?)

This is the kind of benchmark I like to see for any technology.

Anyone know of anything similar for other web technologies?

Gah. That's obvious. But he didn't test the _performance_. That's the real pain of CSS3 versus CSS. Try using box-shadow, or lots of gradients on a medium old machine – then you'll get a sluggish experience.

I appreciate the comparison, and I know it's nitpicking, but those images seem much heavier than they need to be. Using JPGs and/or 8-bit PNGs for the header and sub images could have saved 400K or so.