It’s a huge step forward. Big enough for me to start checking if my webpages work on IE

Some widely implemented CSS3 functions were left out, which is a bummer. I feel like it means that we have to wait a year to be able to use them 100%.
I hate the compatibility button, because it breaks my site completely, so I added the necessary meta tag to get rid of it. I feel dirty for doing that to be honest. Breaks my heart when I have to write a different line of code for each browser. IE9 does support border radius and other stuff without any prefixes, which is surprising to me. I always expect the worst when it comes to IE.
It’s also kind of interesting that the manager pretty much doesn’t work with IE. There are some visual quirks, but more importantly the resource tree does not work at all.