I think they are improving over time. The one I have from a few years ago has a fast GUI, but admittedly has a few annoyances:
The FM radio overloads when I drive near a transmitting tower (the stock radio and an aftermarket Kenwood I have in another car don't have this problem).
It's nice that it integrates with the car's computer, but it could be better. When I back up it switches to back-up cam mode, which turns off the radio or anything else you're doing. This has the side effect that I try to rush through the back-up manoeuver to get the radio back.
I'm tempted to upgrade to a more recent one to see if these things have improved. An upgrade from one aftermarket radio to another is pretty easy, because the wiring is all done.
Yeah, I did this upgrade in the first place just to add bluetooth and figured I give the Android radio a try.