I purchased the LGD with the intention of using it as a lumbar pack while hiking and as a sling (despite being advised against it by the description). I opted for the plain black, because that's most versatile for my lifestyle.
It works beautifully as a lumbar pack - on my hikes, I carry a 27oz Klean Kanteen inside, a small organizer pouch, lunch, and an extra layer. My phone fit perfectly in the buckle pocket, and I tethered my Nik's Minimalist wallet in the zip pocket.
It's not great as a sling - doesn't conform well to my back, but it does have the benefit of being able to adjust the strap from either the top or bottom so that the buckle is in a comfortable location. (Most slings only offer one point of adjustment on the buckle.)
That said, I love the size of the bag, and the size reminded me of one of my favorite bags from my youth, so I bought the standard shoulder strap later. That turned this bag into a really great EDC! Carries my iPad mini in a case, small lunch, 12oz Zojirushi mug, small organizer pouch, pocket notebook, phone, and wallet. The vertical orientation and dimensions of the Cafe Bags (small and medium) and the very large size of the Maker's Bag meant none of those worked for me, but the horizonal orientation and dimensions of the LGD make this a great option for me.