I am using 87U and I have tried R2 PFU limited edition (TKL version), so this is a short personal comparison between the TKL models, but should be the same for full size models. So these are the differences that I have noticed myself:
- 87U has a pleasant 3 degrees angle. I am not sure what exactly is the angel of R2 but it feels slightly bigger/steeper. I am not fan of steep angles, I prefer flat or small angle keyboards, so that’s a negative for me. But the difference is very small, some people might not even realize it.
- Spacebar on 87U is ABS plastic, while on R2 is PBT. R2 spacebar sounds nicer but also feels nicer due to the fact that spacebar on 87U has a sharp edge (which is one of the reasons some people flip it) that can be felt if your thumb finger is not high enough when typing. Fortunately on R2 the edge feels smoother, maybe due to the different plastic material. Please note that if the elevating feet are used on 87U, this issue is much less noticeable.
- R2 case surface feels smoother and a little more premium to the touch.
- R2 case has a little bit more height compared to 87U.
- R2 case takes less space on the desk.