I like the sling body bag design. This is a good size and fits a surprising amount of things (backup shoes, sunglasses, snacks, windbreaker, map, wallet, keys all in one). I like the security pocket so your wallet/passport is against your back. I also love the cell phone pocket in the front which fits my big phone (LG G4) and its big Otterbox case.
HOWEVER! That "breathable ribbon"? It will DESTROY your clothes. It pills the crap out of anything it touches and basically ruined every top I took with me on my hiking vacation.  I have another version of this bag without the security pocket in the back and without the breathable ribbon part and it gives no wear and tear on your outfit while not being any more hot or bothersome.