While I agree that the new search format is bug filled and apparently untested, I do feel that it IS usable. I have only found one thing missing from the previous search page and that is the Match text exactly check boxes. I suspect the option is there somewhere.
If anything, this search form tries to do too much. They combined a "light" search version with their "heavy" search. Perhaps they should have done two different searches, who can say. But all that makes a lot of buttons, tabs, and other things hidden in there. And having too much also makes it harder to test.
I have been simply sending the bugs I find back to them in the feedback. I trust that they are working on each thing. In fact I noticed one issue I sent in has already been fixed.
Patience is the key and a bit of forgiveness, I think.