I'm currently using the new BETA version of Trello and I have noticed that an important feature is missing.
I usually work from the view "My Cards": https://trello.com/u/me/cards
Here I always sort my cards based on deadline and in the version of Trello that is not in the BETA, there will always be a red notification bell and a number of how many unread updates there are in a card. But this notification seems to be completely missing from the new BETA-version of the page.
This is a very important feature for me and without it I'm clueless about when someone has made an update on a card I'm a part of.