>>2224560update: went out a couple miles, somehow STILL not regretting spending my shekels on this
I'm not sure how it does it, but it's definitely more comfortable than my old day pack for carrying the same amount of weight. I think it's something with the angle of the shoulder straps and how instead of going straight over the top they cross from the outside in and transfers the weight to shoulder bones better or some other finnish black magic idk.
>>2224561I've been swinging it around and haven't found any leaking from the flap yet, but it does like to leak a little bit where the mouthpiece connects to the tube. Not a big issue since it just drips on my shirt a little and it's already soaked with sweat anyway, but I'll see if I can find something to wrap around it to provide a better seal there.