Just tried the new Blogger interface and what an abysmal ride it was. Couldn't edit an older post, couldn't publish the new post on first try, couldn't preview, and when it finally posted the format was nothing like I had wanted. So I had to delete it.
When I tried to go back to the original interface I was given the option to leave feedback so I did...but after I sent it off I received an error message suggesting that my feedback was lost...so I guess they don't get to know what my problems were?
Thankfully I was able to get back to the original interface.