I have a mid-size Vera Backpack, with padded straps and LOVE it. I think I went thru 3 (maybe 4) other cross body type bags for the parks first, and finally bought a Vera backpack. It's much more comfortable and lightweight than any of the other bags (many recommended on the dis boards).
In my opinion I think the Campus is a really large, and I try to avoid carrying anything larger than I need in the parks. I went into the stores and tried on various fits to see what I thought would be best. The smaller backpack doesn't have padded straps, so that was out, and I think the medium (can't remember what it's called and likely a newer version now), was perfect. I carry a small camera though, not a big DLSR. I carry water bottles for the whole family, and snacks...can't think what else, but feel like I carry a lot and surprised at how much fits. If you need a change of clothes, you could always put that in a locker so you won't have to carry it around all day.... Also, I use a Vera Bradly little zip id case for my 'wallet' in the parks to save room in my bag.
So I can't say for sure what others think of the Campus, as I don't have that one, but I highly recommend a Vera backpack!!
