As always, I get the great honor of reporting that some of this doesn't appear to work in Firefox, which is my primary browser. I use the developer edition.

Things that don't work as compared to Chrome:

• Up/down reordering
• Webfonts

Things that do:

• Image sizing / placement
• Text editing + new paragraph block

Things that don't work in either (assuming expected):

• Adding a new block beyond the ability to hit enter for a new paragraph block
• Filtering/searching of block types
• Text alignment