Aer bags are great. I have this exact one and a larger brief/backpack hybrid from them that I take to work.
Love using slings.
Very annoyed at the trend of placing easily-disengaged buckles (especially the super trendy costly fidlock ones) onto the straps that sit on one's back and thereby making them easily-snatchable. Sucks that so many of the nice ones (like Peak Design, Aer) are going this route these days; feels like justification for new product revs rather than practicality. This might be just a personal annoyance, as I'm a front-wearer whereas it seems most wear slings on their backs, putting the buckle in front.
I don't have any experience with the Fidlock but I'm guessing the straps are held together with a magnet rather than just the usual bulky plastic clip?
I plan on wearing it across my back but occasionally my front, so would tightening the straps to fit snugly across my back/chest make disengaging the clip harder?
Thanks!