I have a hard requirement before I can pull the trigger on a keyboard for my iPad: I need the same amount of control over keyboard layout that I get with Karabiner.

Specifically, I have caps lock mapped to backspace, and "delete" mapped to actual delete. This is deep in my muscle memory and I'm not interested in changing it.

I'm keeping an eye on things, and when I see that this affordance exists I'll probably get one. There are times when having a touchscreen laptop with a built-in cellular modem is just what I want.