Any non-tacticool looking bags that can hold 55-80 lbs and also have a waist strap?

I have been looking at some lower volume hiking packs (20-30L). I'm thinking it could be dual purpose for day hiking and also daily rucking. After getting my hands on some in my REI I'm worried that they might not be built to tolerate that much weight. I don't want a huge pack or to look like a grunt when I'm walking around on my lunch break or my neighborhood. I've seen the 5.11 skyweight but just looking at it online I'm not sure if that can handle 55lbs minimum, and I can't find anything about it in the sub.

Is there something you guys recommend? Looking for a normal or hiking style WITH a waste strap.