Going Frameless? Will my back regret it?

Yep, the gorilla has a removable aluminum stay…which I removed. It does use the sit pad (as seen in the previous post's G4) but honestly I didn't notice any difference with or without the stays. The sit pad gives it nice structure without the stays and carries very well. Having used the more substantial ospreys and Gregorys I really think its a stretch to equate those frames with the little piece of bent aluminum in the gorilla. Perhaps in a purist view of frameless…but functionally I think the gap between those product types is quite large.

Maybe if I topped 20# I'd try the stays again, but so far my weekend jaunts with it have been <15. Having the flexibility is nice.

Having pulled apart some of those frame packs (a Deuter, most specifically, but one without the suspended mesh backpanel), I can say that many use a surprisingly similar system to the Gorilla. The Gorilla is something of an odd hybrid, being able to between framed and frameless.

However, I don't know what kind of alloy the Deuter pack used. I have heard that the 6061 of the Gorilla is quite common in mainstream packs, but I can't say for sure.

Yes. So far, all the GG packs I have tried fit the 5 piece pad, it looks like it is pretty standard on the older G4, both G5's(spinnaker & sil,) the Miniposa and the Murmur. The material stretches when new, but quickly learns it's place.

She never got a chance to cut and tape her nightlite (she's works as a RN, has two kids.) I will probably do it for her since last summer bothered her. Yeah, inside seems to work better with the inflatable pads…hers crushed easily from the weight, especially the bottom edge…it was not supplying enough support for all the junk she brings…books, newspapers, towel, bag, water bottles. I have the rest of the camp in my pack (tarp, cookset, food, sleeping bag.) Using the pad pockets for more than 10 pounds of gear is kind-of wasted. I thought the pad would be OK since she wasn't carrying a LOT of weight(~17#,) so, OK'ed it. That was my mistake.