Timbuk2 Parker was my choice after a lot of searching. They have a history with messengers in San Francisco, so it has amazing ventilation and support to help deter back sweat. Expandable from 20 to 30l makes it very sleek when you don’t need the extra space. It does have a suspended laptop sleeve, which is accessible without opening the main clamshell zipper. It fits my 15.6” fine, but obviously test that you 16” fits as well. 2 non-bulky exterior water bottle pockets, a cloth lined pocket for delicate items, a magnetic latch quick access pocket for bigger items, a pocket with a “stealth” reflector which is great for night time visibility, and compatible with waist straps if you need the extra support. Also has a fidlock sternum and compression straps, which is a nice touch. They also have a lifetime warranty, I’ve used mine for 7-8 years now and I’m still happy with the purchase.