We've used a Bear Vault for many years. Works fine, and opens without a tool. OM makes a good point about packing it: it's a science once you get it down. Take the air out of every sealed package, limit the amount of packaging in general. Cram, cram, cram. If you are good, you can get food for two people for four days into the larger BV500. And since you can carry your first day's lunch and dinner in the pack and outside of the BV, that's a five day trip for two--ten days for one!

I carry mine upright in my pack. First I pack my sleeping bag and pad in the very bottom of my pack--since I won't every need that until the end of the day. On top of that I pack the BV500, upright, and slide the tent down next to it in the pack. I can usually wedge a few more things, like a fly rod or loose clothes, down alongside those. On top of those go my light things: clothed, raingear, puffy jacket, etc. Those I might need on the trail.

Outside pockets are for water, water filter, lunch, and the odds and ends bag I carry with mosquito net, bug spray, bandana, etc.