So, I'm afraid I also can't stand the new UI.

On the flight search page, ironically, I'm drawn to the date picker first, before trying in my origin and destination airports. I then need to go back to those. Overall, it seems far less keyboard friendly and the flight search form takes longer to input the data. Trying timing someone inputting the data in the old and new systems and you'll see what I mean.

The flight search results page is even worse. The fare bucket display particularly is really poorly formatted. If you actually wanted to be useful and innovative, you could put the different fare class results on different lines by cabin, such as:
F9 A6
J9 C9 D8 D6 I0
W9 E5 T5
Y9 B9 H9 K9 .... G0

That would actually be useful and you can see at a glance, with details, as to how busy each cabin is.

Echo all the comments about too much wasted space. Definitely want to see more info on the screen, especially as I find it most useful on a desktop or iPad.

Edit - I can see that you've done this under the disclosure triangle. This takes up even more space! I should be able to see this at a glance. I don't need the "headings" saying 'First', 'Business' etc. This is expertflyer after all.

Basically at the moment, if you get rid of the old interface and impose this on us, I'll cancel!