Compressed mode for message list.
The new Beta UI looks good over-all, but the message list (at least on my screen) is 2/3rd white space which means my standard browser window shows me 8 messages. Dropping that white space by half would still look good and double what I can see with a single glance. I can imagine that some would like to see an even denser mode, but the current options are way too sparse.
Yes. Coming from Gmail, the density of messages is too low, with lots of unnecessary white space.
[Deleted User] commented
Agreed - the initials of the sender in the circle on the left side of the message list makes each row take up far too much space.