I fly pinch but have tried both. Pinch is more comfortable for me and I like that I rarely lose the stick and make that "doioing" sound that I hate. I was surprised that for the most part,I could fly just as well either way with a little practice,but thumbs still feels sloppier to me.
I don't see using expo as a crutch or a way to cover up poor technique unless perhaps it is being used on a trainer. It seems to me that we typically set up our planes these days with way more throw than they really need to achieve the ability to do radical maneuvers. Imagine if you set your car up so a quarter turn of the steering wheel would make the wheels go 90 degrees. Then you'd probably NEED expo just to be able to drive normal. I see expo as a way to have high and low rates available to you,without having to stop and flip a switch.



Edit:
Ooops....When I posted this,I didn't realize It was in the pattern forum. So some of my comments were made with sport and 3d flying in mind.