Both are great bags, but I would go with the Revo bag! The horseshoe disc opening has never been a problem for me. The discs on both ends are easy to remove. Plus, if it turns over, the discs stay in better.
The drink holders on the Revo have a small strip on the bottom. So, small bottles would fall through, but you can fix it pretty easy.
The GB bags have horrible small zippers. The GB bag is lighter, and has really cool pocket placements. In my opinion, the frame on the GB is stuck together junk that you can get at Home Depot.
The Revo bag has the truck vinyl bottom, and two huge pockets. I also like the shape of the putter pocket better on the Revo. The frame on the Revo has never been a problem for me, and it was actually manufactured for the bag. The zippers on the Revo are big and amazing.
I've had both bags, and I disliked more things about the GB. That's why I will stick with the Revolution bags! Plus, Dave is amazing to work with!
You wont go wrong by picking either brand, and they are both made in the USA. I'm just giving my honest opinion, so don't turn this into a Revolution vs. Gorilla Boy fan boy thing!