So, here are my findings after extended use:
At first they feel really weird as (in difference to a chair armrest) they move around WITH your arm (but that's actually their main advantage).
It takes some time getting used to em (1-2 weeks), but after that you almost won't notice em anymore,
and if you try to work without em after that you quickly realize how nice they actually are.
One thing I noticed is that the correct mounting position is very important,
because if they are mounted too close or too far you get the effect described by Findecanor.
Linear movement get turned into circular movement by the pivots, but if you set it up right linear motions work well (within a considerably work-area).
It seems that a distance which results in a "Z" folded shape (see image) when reaching your work area works best to maintain linear motion capability.
Another thing I noticed that I prefer to rest the forearm area close to the elbow on the pad (instead of the forearm area close to the palm).
Feels much more natural and less "restricting" to me, especially for mouse heavy applications (Gaming, Photoshop, etc.).
Overall this armrests are really nice, good construction and they work well for gaming and typing alike.
Probably gonna order two more as backup (even tho I think they will last extremely long).
