ULA vs Gossemer Gear

I don't have the Circuit, and have only studied its sizing based on reviews as I am considering a possible acquisition.
I do have and use the GG Gorilla.
Don't get fooled by Gorilla's claimed volume – it is simply a sub-30 liter pack (main body), the rest of the claimed volume is to be fit in side and back pockets, plus its extended collar. However, if you try to utilize the collar, you might be able to use another 5 liters before running out of length for closing the pack in a reliable fashion due to the design of its top.

Volume-wise, the ULA Circuit is a true 40-liter main body, plus a quite usable extension collar. Pockets volume galore, much more than the Gorilla.

If your total volume (food included) is less than 45 liters, you might be able to get by the Gorilla. I use it for 3 to 4 days trips, but it is not suited for 5+ days. Unless you are one of those hikers loving to have their gear hanging outside of the pack, screwing up the overall CG of (pack + hiker)….
Also, its comfortable upper weight limit is around 25-26 lbs., while the Circuit would be comfortable with up to 35 lbs. due to a better belt and overall suspension.
The Circuit appears to be a proven long-haul pack, although I'm not giving up on the Gorilla for short trips as it is a bit lighter.

Tough choice. Having backpacked with both, the ULA Circuit has a larger main body volume and sat higher on my back than the Gossamer Gear Gorilla . The ULA Circuit has a cavernous roll top but it has to be unrolled to get something; with the GG Gorilla top flap, there was some unrolling but not as much – that little pocket could squeeze in a TNF Anorak also, both have little hip belt pockets, but a bit more main gear could go inside the Circuit I felt. The ULA was a bit better in compressing a larger load for my shoulder season packs but for summer, I switched to the GG to catch some more breezes as the Gorilla sat below my shoulders. Slight difference certainly but when it's hot, I prefer less pack. Kind of comes down to aesthetics. Both have some netting but the Circuit has a bit more. The frames are different. GG uses an aluminum upside U that's removable while ULA Circuit had a single stay. Both great lightweight packs – just one seems a little more elongated (the ULA) with more cargo inside, …while the other seemed more squat (the GG) but good for summer ventilation, not interfering with a hat. ULA does custom work so you may ask if they'd leave the netting off or replace with a fabric pocket.

Conclusion: I liked the Gorilla for hot weather hikes with minimal gear + some water + being able to remove the frame, but liked the Circuit to pack more gear for mountains (neither worked for my torso btw so I went with the Zimmerbuilt ZB-2)

If you deal with brush then the stretchy back pocket of the ULA packs will be a problem. I already tore mine up on chaparral and had to cut it off. I hear they do custom work so you could ask them to put a regular nylon zippered pocket or do it yourself (that's what I plan to do.)

The ula fabric seems durable enough for most bushwacking, I've done some rough bushwacking with it and it's been fine, but I'm not sure how it will hold up over the long term. I might end up getting a full dyneema ohm if I ever wear out my standard ohm. But the ULA packs are definitley on the more durable side of ultralight packs.

Ula uses 210 dyneema and 1.9 oz ripstop.

I'ved used both packs and honestly, they are pretty different.

The ULA is literally bomber, the circuit, in my opinion, is HUGE, and far more robust. It was actually TOO robust for what I use it for, which is one reason why i sold it. The ULA frame is an actual FRAME – a huge block of material along the back. I did not like it very much, but for those who want a good solid frame, this is the way to go.

The GG is my favorite pack by far. But it won't carry a bear can (comfortably…IMO), it won't carry more than 25 or so pounds (comfortably), and the back pocket certainly won't hold up to nasty bushwhacking.

For what you are looking for, I'd HIGHLY recommend the circuit. It's a great pack.

Just to be clear on the ULA frame. It has an upside down U suspension hoop, that flexes as your hips move. It ALSO has a flat, aluminum, center stay that is bendable to fit your spine and is removable.

I've never used a ULA pack but my buddy has the Ohm 2.0 and he loves it. I do own the Gorilla and love it. I was about to use it on my thru hike this year but decided against it and keep it my section pack. That being said, the pack is very comfortable with a 25-30 pound load. I don't think you can go wrong with either pack. Only thing with the Gorilla is there are no load lifters which might be helpful if carrying a heavier load. I never found the need for load lifters with that pack personally, but I know some people feel more comfortable with them so they can pull the load closer to their back. Hope this helps and good luck with your decision.

I've had a number of both GG and ULA packs and liked them both but in the end, I sold my GG packs and kept the ULA packs. I agree with what the others have said about volume: the ULA packs are bigger, volume wise, for similar stated sizes. The big seller for me however, is the awesome shoulder straps on the ULA packs. I am a big guy and the S shaped shoulder straps prevent any rubbing on my neck, a constant problem I had with the GG harnesses. I also like the ULA waist straps better. I have the Circuit and the CDT and like them both.

I heard the same issue with the GG packs. I guess they actually spread out the straps up towards the neck on the new models. I only have the new model so I don't have experience with it. I could be wrong though.