[rgibson]

I like the new AJAX functionality in 4.3 and the revised admin area. The inclusing of the AJAX minicart resolved several customer experience issues. However, some of the changes in the program logic has made integrating mods that were created for 4.2 entertaining.

If you can test in IE 6/7, or get some one to check for you, make the changes. If you need a cheap way to setup a IE6/7 environment, take a look at virtualbox.org, you can setup some virtual machines on your dev box with IE6 and IE7 for testing (if you have some old windows OS licenses to use). I found several rendering issues on my site, due to my layout changes, in 6, 7 & 8 under xp that were not caught testing in just ie8 with vista and win7.