Just burned an audio cd and it seems to be working as expected. Just some of observations:
* It doesn't seem possible to remove files once you add them to the list of files to be burned. You can uncheck them but deleting them is not possible.
* I really liked the idea that you can just drag and drop files, makes things so much easier. But to take better advantage of this I think it would be better to able to dock the burner window in the same way it is possible with the tag editor.
* Burning at low speeds doesn't seem possible like 1x, 2x, 4x etc. Not going to use it myself I know some people tend to use such low speeds for serious work when they want a "perfect" copy.
Other than these 3 things I found the new burning functionality really good and sufficient for my needs at this point. I will come back to you if I find anything else worth reporting...