I have both of these and the heavier greyback packs fine in my opinion. Walked it it miles and have carried it while mountain biking in to my stands. Awesome stand, extremely comfortable. However, I think you'll like the Greyback Elite better. It doesn't have the bar in your way and it has in my opinion a more comfortable seat.
Gorilla Climbers are easy to use, comfortable and the storage pockets come in great use for gear and snacks.