Had Crow 5 point harnesses with the rotary buckles for about a year now. Work great, right side up or upside down. Belts come extra long so I still need to trim the bitter ends.
 
I have flown an RV with the Crow rotary cam lock mechanism. Very nice. Easy to lock in and easy to get out of. I bought a set for the bird I am building.
 
I recently upgraded to the Crow Belts and Ratchet as part of installing a crotch strap in my 6. I have yet to fly with them. I am very impressed with the price, quality, and service.

I went with the 2" belts, same as stock Van's. They actually measure about 1 7/8", but are certified and tested well beyond anything survivable.

Many use 3" belts, which are quite wide and a bit bulky in comparison. Although I have not flown them, I think they will be a bit more comfortable than the 3", at least they are on the ground! (not that that counts.) This might be more personal preference than anything.
 
Recent Crow purchase

Have only buckled in to make airplane noises but happy with the set. Cam lock.
 
For those of us with the older rotary buckle, can we replace it with the pro formula cam lock, while using our old belts and fittings?