These are items (excluding hybrid and thread view) that are very disappointing with the new board format:
Limited smilies... not really a big deal but something I used
I can't use my EZLinkPreview extension (Chrome). This allowed me to open up a thread in a floating window to read without leaving the RSS thread content page. This was a huge timesaver for me.
Although the new format is easier to read on my cell phone (because it is so large), I can only see one post (in a thread) at a time... and I've got a Samsung Note 3 (and yes, I know how to shrink the view).
I'm certain there will be other things, but these are the ones I've noticed.
