I used it today in the field and other than obstructing the 5D button, found it quite good. The remote is out of balance, but whether the tablet is in front or in back, it's just going to be that way unless you put a counterweight in the phone holder. However when using the lanyard, that takes at least some of the weight off the remote. Most lanyards are too long for me as I have a very short upper body, but I was able set the length of this one OK. Perhaps I can use the skycreate tablet mount that I had been using as a counterweight or make it into an armrest.
I don't use the 5D all that often either, but i have left for -EV, and right for +EV, and somehow bumped it to at least one EV in the minus direction. Normally if I realize this, I'll use the 5D to increase it back to 0 EV, but that wasn't possible.
It might not be feasible, but it would be nice if it could be designed where the part that clamps around the remote could flatten when not in use.
I mentioned that the vent holes in the front seem to be blocked. It could be me but it seemed the remote got a bit warmer than usual on the left side.
Otherwise it is excellent.