The new HAWG or the older one?
The older one has a lower compartment that sticks out from the main body, the new one is flush.
The HAWG is fine for a day pack in a neutral climate, if you're anywhere that runs the risk of freezing at night it's a bit small unless your shelter building skills are sharp.
It doesn't offer any support for loads
About 15lbs would be the MAX I would try to carry in one. That includes water and food weight.
I used to use the old style HAWG for my patrol pack, full bladder, an MRE, a small warming layer, change of socks, foot powder, extra batteries and some extra pyro and ammo was the max load for it.
Honestly, unless you're getting a screaming deal on it($50 or less) I would look at something else.
You can get a small pack that has a frame and is MUCH lighter for around the same price. Any of the Ultralight day packs are going to carry about the same as the HAWG, weight POUNDS less, and have the same or greater capacity.