I think that the latest Inbox update made it less convenient than it was before. Here’s why:
With the new UI you have to make 2 clicks to switch between categories (All/Assigned to me/@Mentioned/Assigned by me). Before the update it was just 1 click.
The filter button jumps from left to right when you switch between categories if one category is empty and the other one have some notifications in it. It is very frustrating and unconvenient (see the picture).