I’ve used many different belay devices. For a lot of my climbing, my partners take a lot in order to figure out sequences. So for me, my preferred device is a grigri (it really doesn’t matter which iteration), but I have a bad and expensive habit of leaving them at the gym and people steal them :(
I’ve used a megajul a fair bit but I will say it has one major flaw in my opinion. A number of years ago I was belaying a leader and at one point during the climb I was paying attention to them and not my hands. I had inadvertently put my thumb in the rope loop instead of the handle loop in the front of the device. If the leader had fallen off at that time, my thumb would have been amputated. It really weirds me out how easy that is to do on that device.









Well here’s a nice example of a Streisand effect.