I have both, well for the Arcane I have the Large version. Alpaka has better internal organization. I don't like the J-zip on the Arcane, but I have gotten alot of comments from strangers -- ooh osprey, nice bag (if that matters at all) They both don't have much capacity though.

Whatever you choose, can't go wrong for travel purposes.

I have both and I love either of them. The Arcane ist easily the most comfortable bag for me but the Alpaka Metro is close. Overall I prefer the Alpaka because of its front pocket. It's very tight so when a few times I forgot to zip it close, nothing fell out and the zip is on the "right" side for me. Also in rainy weather I would trust the Alpaka more than the Arcane though I never tested my hypothesis so I never had bad experiences with the Osprey.

Osprey almost certainly has the advantage in quality.

Have both, love osprey better. Alpaka has more organization but I hate the zipper on that bag. When the waterguard part is closed you can’t open the zipper. So you have to undo that first. My vote for osprey, I have the bigger version in yellow and absolutely love it.

If you’re looking for a small bag, have a look at the Chrome Industries Ruckas 15L. I looked at both the bags you’re considering, found a random review of the Ruckas and went with that’s. It’s perfect for me

I really enjoy the Alpaka, it’s very good quality and really comfortable.

I don’t know much about backpacks, but the Osprey looks nicer than the other one. 👍🏻

I haven’t tested the Osprey, but the Alpaka is one of the most comfortable bags I own. And I’ve carried a pretty heavy load in it (think, a couple batteries, a switch, a water bottle, etc). It’s one of my favorite bags.

I would typically put more stock in Osprey