Small packs are often interesting, because they have to focus since there's not enough room on the pack for every option. Gregory always makes interesting packs, because that's pretty much all they do. Combine that dual focus and you end up with an outstanding pack like the Gregory Sula 18. The irony here is that this pack does a whole lot of things very well, thanks to clever design and a feature you don't often find on small packs: a frame.
At first glance the smooth and svelte Sula 18 is clearly a day hiker, with a smaller capacity appropriate for fast and light excursions. Look closer, however, and you'll see the technical features that are the mark of a true multi-role pack: an outside stuffer pocket, outside zipped and padded pocekt, internal hydration sleeve with both loop and hook, internal zipped organizer pocket, ice axe/trekking pole loop, dual mesh water bottle pockets, compression straps, a minimalist hip strap and glove friendly zipper pulls. When you realize it's also got a fairly stout little frame on it, it suddenly dawns on you: I could stuff this thing to the gills and use it for anything, and in any season!
And indeed you can. The Sula hits all the right notes to be a quiver of one for a small pack. For winter climbing, it'll carry an axe and crampon pouch. For summer cragging, plenty of fluids, shoes, rope and rack. For ultralight overnight, a tarp, food and summerweight sleeping bag. It even excels for school use and travel; there's way more organization than you would expect on a pack this size, and you can put a mid-size laptop in the hydration sleeve and the frame will keep it from bouncing off the floor. There's even load-lifter straps, a sternum strap and keep loops on the shoulder straps to dial everything in once you're loaded. You can also reverse the hip belt to function as a lower compression strap for smaller loads and lighter days.
The frame is really the key to this pack. You can put a deceptively heavy load in it, but thanks to the frame and hip belt it'll carry like a champ. The other big plus for the frame is the airflow. It's been a hot summer everywhere, and the Sula 18 means your shirt won't be plastered to your body within seconds of starting a trek. The Sula 18 is a beautiful pack, not just on the outside but on the inside where it counts: the frame, that is. Absolutely consider at the top of your list if you're looking for a do-it-all small pack.