I'm not talking about loading the dog up with tent/groceries/camping supplies for the week, LOL but I've been thinking about a backpack or saddle bag size/weight appropriate that can hold (speaking for Orson) a couple water bottles, wallet, spare leash, maybe a snack, and/or bandaids-first aid stuff for a hike. Get more doggie bang for his buck on the hike.........a bit more workout. Do you have an opinion about them? Have you used them? Any advice in general? Perhaps a view point I haven't considered?