I have a G6 with over 450 miles on it now. I did not seam seal it or otherwise reinforce the seams in any fashion. I noticed a couple of weeks ago, at one location, the seam is starting to separate a bit for about 1.5" in length. Though there is no hole or complete seam separation yet, it is something I'm going to have attend to so that it doesn't progress.
Not sure of the "mileage" others are getting out of their G6. I "baby" my gear which may take the fun out of hiking for some folks - to each their own is my feeling and more power to you. I don't overload mine, either as regards weight, or volume. Rarely above 15lb even at the start of day one, always below 15lb at the end of day one, and often start out with ~12lb fully loaded pack wt for a weekend (2-2.5d food). It's a warmer weather pack for me, so less relatively bulky, insulating/cold weather gear.
I'm happy with with 450+ trail miles on the pack. Good Price per unit mile value. This is UL gear, and we know "going in" that it will need replacement more often than heavier, more robust gear. That said, 2.2 silnylon sounds like a good option for a Thru-hike version of the G6. Still, sans hip-belt, unless you're very stoic, 15lb might be the upper carrying limit - so keep that in mind when considering resupplies.
Some Observations and Questions for the more experienced:
I've never done a Thru-hike, but I can't help but think more volume and/or load carrying capacity might be in order to stretch out the number of days b/t resupplies??? Somehow I got it in my mind that 7-10 days b/t resupplies might be nice? 10d food might, alone, be 15lb - at 1.5lb/day. I've had 22lb in a G5 (once - never again; but, hey...that's just me...i'm a wimp), with 15-18lb the usual comfortable starting fully loaded pack wt. A silnylon G5 might be nice. Now you're getting into SMD Essence pack empty wt (~13oz or so GVP told me a year or so ago a 2.2 G5 would probably weigh), so you now have another option - though the Essence is ~600 cubes smaller than the G5. So, at this point, you could also for 3-4oz more go for an internal frame GG Mariposa pack. Others have used it for long distance hiking, I've read, and you can carry 25lb (extra food for longer resupply intervals if that is desirable.) If you really want to stretch resupply out, next step up might be the SMD Starlite pack and load in the food for 30-35lb pack wt (will it all fit???). Can an old man, like me, do 20mile days on the AT when carrying a 30-35lb pack at the start after each resupply? Or, will I have to make up the distance with 16hr hiking-days to get near 30mile days when the pack is lighter, nearing resupply time?
I'm just guessing here (yeah...I know...it shows), not having done a Thru-hike, so I'd really like to know what an experienced Thru-hiker thinks of going 10+ days without resupply. Is there any point in doing the entire AT with 10 or less resupplies? Is it even possible? What other factors am I missing/ignoring/forgetting in going longer without a resupply? Guess you can tell that I don't have a clue!! If you are so inclinded, I would appreciate learning something from your experience. Thanks in advance for the replies.