I got my RDS2216 in today!
The disk trays are as flimsy as something that came off a 3D printer, so you're not going to be frequently hot-swapping with these.
There's an issue with this side, however. The screws wouldn't go in straight. We loosened a few of them and kind of jiggled it a little to get the dog ear to work, but the screws still felt like they went in at an angle.
Here it is racked up in the lab for initial tests (and I don't have 40G/100G networking anywhere else yet).
I'm working on a short video and we'll go the rounds with it.

That little black box with red tabs on it is six SATA drives going into a CCR2116. We'll see how they compare.

Are we having too much fun?

Not impressed for now. The deployment of many Docker containers is painful. I bought it exclusively to deploy things like Victorialogs and Akvorado and I am hitting a wall.
Not the entire fault of Mikrotik though, many providers are using docker-compose or weird Dockerfile. I am sure it will become better in a few releases