I'm sorry to say that rotoscoping in After Effects has not seen a drastic improvenent. It is usable, but still laborious.
I had thought with support from Sensei theree would be drastic improvement. Not so.
I had a project rotoscoping individual solo dancers from a black background. The dancers were in full fill light.
This should have been a relatively easy task.
Unfortunately, it was not.
Honestly, it would have been faster taking the 115 or so frames from each of the four video clips into PhotoshoP, use select subject, then exported then back out to AE.
Roto needs to be retooled to go through two selection processes before you even get to the brush.
First, it needs to go through a contrast detection process and make an initial selection based on contrast.
Second, it needs to refine that selection using a focus detection pass.
Then the user can remove items that are not part of the desired selection using the roto brush and refine the actual selection
As it is now, roto brush is essentially the same as it was before.