I've been impressed with its comfort and it's durability.
It has a number of features worth mentioning; firstly the DTS (Dynamic Transfer Suspension) refers to the system that stops the pack from compressing and transferring all the weight to the waist belt when you've stuffed it full of ropes, gear, harness and boots. It is designed to distribute weight between the belt and shoulder straps. Secondly the Jetstream part of the name means that the pack has been designed to prevent the inevitable sweat that comes from working hard from gathering too much around ones back.
It did what it says on the tin, transferring weight very comfortably between back and waist, the waist strap is very easily adjusted and along with all the other straps, zips and clasps it is all well designed and robust. It also kept me reasonably well ventilated despite wandering around a very hot Rodellar in search of a free route!
Other features I like are; a front opening section to gain access to the lower half of the pack, side mesh pockets which are thankfully very tough as they get lots of use with water bottles constantly being taken out and pushed back in, ice axe loops, a separate area inside the main body ideal for a few clothes, large pocket in the lid with the essential key ring tie and finally, handy waist belt pockets that can be accessed when the sack is on your back just big enough for a small snack or mobile phone. One other thing I can't quite figure is that I seem to be able to get more in this 35 litre sack than I can in my old 40 litre sack. It happily swallowed up three pairs of rock boots, spare clothes, gear rack, harness, rope, lunch along with flask and water. As this is the only Gregory pack I've used I'm not sure whether this generous sizing is across their whole range or unique to the Z35 but I like it.
the Z35 is an excellent day sack that feels very comfortable
In conclusion, the Z35 is an excellent day sack that feels very comfortable, has some great features, is robust and has enough space for UK climbers.
Weight: 1.4 kg
What Gregory say:
The Z35 uses our JetStream™ DTS technology so the weight of your gear rests directly on the waistbelt while the Aero-Tech mesh backpanel allows for airflow across your back. Perfect for super technical routes or longer trips that require more gear, the Z35 has space for everything you need.
Also available in a female fit version.
UK Only: Free raincover with each purchase while stocks last