Man how centers are different. At ZME in most areas D-sides don't hardly do anything with the scope. They are there to take and make points and coordinate over the line, that is about it. I would say that 95% of trainees can get their D sides here, it is not that difficult. IMO, a lot get checked out that should be but, no body cares about my opinion.
R sides is a different story. I would say about 50% wash out in either R school or on R side OJT. R sides generally take care of everything on the scope. Most don't like the D side to touch anything. Maybe move an overlapping data block. Only make a handoff if the auto hand off isn't working. Maybe offer a suggestion on separation. Not much else.
I can see the benefits of both ways of training, and each has their good parts. I wish we washed more people out sooner, and didn't waste their time. There are too many stories and people who just bought a nice house/car or whatever and then they wash out, all because, they though they were the shiznit on the D side. Not to bash the position, but honestly, I could teach someone the basics of the D side position in about one day. Anyone can do it.
I wish the agency would have pernament D sides. It would be a nice little career for some to make maybe like 50K in a center. That wouldn't be a bad little gig.