I've been using a couple different HPG kit bags for years and I love 'em. I've got lots of HPG stuff, plan on getting more, and recommend their gear a lot. It's high quality, tough gear that works. What initially attracted me to HPG was an online search for a discreet yet practical backcountry carry method, and I landed on the kit bags.
Food for thought...
One thing I've experienced here on the east coast is that, unfortunately, for whatever reason, the bag screams "gun!" I've been called out on the bag/gun on separate occasions while backpacking the AT. Each time it was an issue it was different very antigun hippies with unprovoked antagonistic comments like "whatcha got in your bag there?" and "good thing you have that gun out here" and " what are you afraid of that makes you carry a gun out here?" and so on. Not to mention, it's apparently a dead giveaway to other "gun guys" as well, as it has sparked a couple "whatcha packin'?" convos I'd rather not have.
I have both "ranger green" and "coyote" colors so maybe the colors are a little too .mil or something. I never wear any multicam crap or LE stuff or anything at all like that anywhere besides work, so I really don't think it's me. I've always been able to dissuade any attempt to create a problem from anyone, have just kind of laughed it off or whatever, but having to do that kind of defeats the purpose.
Having said all of that, I have to reemphasize how much I love the kit bags and I still wear them hiking in actual wilderness areas, while hunting, fishing, etc, but I try and avoid wearing them in more heavily travelled areas. I know HPG has offered some different colorations (gray robic, etc.) over the years, and maybe that's the solution. Or maybe I should use a good old fashioned fanny pack for some occassions...but I'd rather not though.