Of a couple of 'em...
Back in the day I lived in the Sierra Nevada and hung food. Hated it. What a pain, tying up rocks, finding a tree with a branch that works, yada yada. As one who loves treeline and above, hanging food was extremely irritating.
Used a Garcia a couple times, thing was heavy and huge.
Then I got a BearVault BV450 Solo. I actually really like the twist top (even in cold temps, it was easy to open and didn't need any tools to do it). And I also really like that it's transparent. Easy to find things. And the wide opening is really convenient as well. It's really been great. LOVE that I didn't have to hang anything! Forgot to brush my teeth? No problem, didn't have to bring down my hanging stuff-bag mess just to get the toothpaste.
Then I got more and more into photography, and with 10 pounds of photo equipment, and my legs not gettin' any younger (go figure), I started the process of lightening my load (I hike solo, so whatever I need, I have to carry).
I downsized from an Osprey Aether 70 to a Granite Gear Blaze A.C. 60. After that, I found that the BearVault was just a wee bit too heavy and too big, so I wondered if there was anything a bit smaller.
Then I saw the BareBoxer (yes, it's spelled Bare) Contender online and went for it. On my small scale (EatSmart Precision Pro) it's 26.7 oz, or 1.66666- pounds. So a tad heavier than advertised. But who knows how accurate scales are. Philosophically, how does one ever truly know? Do you have to buy ten scales, weigh everything and take the average (minus the scores from that one judge from Germany)? Let's say your scale is off 1/2 oz and you have 30 items (large or small) in your pack, that's 15 oz or about a pound of difference. But I digress...
Anyway, love the size, the weight savings is nice. It's basically a baby Garcia. The BearVault on my same EatSmart scale is 33 oz, so 6.3 oz savings and again, a bit smaller, but that smaller size is much more convenient. Fits my Blaze really well now; the BearVault was just a bit too large and made it pack funny. The opening is a little strange but makes sense once you get used to it, and I do have a multi-tool (I know, I'm not a true ultralighter) that makes it easy. My only concern is just that, really: needing a tool to open it.
I miss the transparency, the larger opening and the tool-free operation of the BearVault. But the compromise is worth it. I've toyed with the idea of getting the ursack, but the comfort of a hard-sided bear canister that I don't have to tie up anywhere is at this point worth the tradeoff. It takes me 30 seconds to deal with my food once I'm done eating and such. I walk a few dozen yards from my campsite, and I'm done. I don't have to care if there are rocks or trees for tying and all that.
So if you have any questions that I haven't covered about the BearVault BV450 vs the BareBoxer Contender, fire away. No, I don't intend on selling my BearVault at this point. It's the perfect size for when my wife and I backpack together, and I don't see any 5+ night jaunts for us in the near future.
Added: Oh, and as far as fitting food into it, I think I could fit a 4-5 night trip in it, HOWEVER I do not cook on the trail (weight goes to photography equipment). Well, 5 might be pushing it... BearVault could handle 5-6 nights if all cold meals.