I have one of Abel armrests on one of my guitars and it is actually very well designed and functional. It is also very comfortable, maybe the most comfortable of the several armrests I have tried.
The drawbacks are: it's not exactly beautiful, and it has to be removed when puting the guitar into a case.
Apart from that it's a great product doing exactly what it is supposed to do, and, above all, really staying in place, because no sucction cups are involved.
Music is a big continent with different landscapes and corners. Some of them I do visit frequently, some from time to time and some I know from hearsay only ...
My Youtube Channel is: TheMusicalEvents