I use it for multipitch trad climbs and it works great. If you don't fill the bladder all the way full, you can fit a rain jacket in it too. It sits nice and high on your back, so it doesn't interfere with a climbing harness or chalking up.
No mesh thing/bungee cord on the back to hold extra gear.
Good for quick rides or runs. Holds enough water for a short outing. Very comfortable pack that allows you to pack the basics. Easy to refill and clean.
If you need anything more than a set of keys and a flat kit, you will need a bigger bag.
