Here's a quick peek at No Excuses' 1/2 Pack bags. Capacity-wise, they're right around a Crunch Box. I fit 10 in the main compartment without it being tight (I built the plastic frame inside quickly just to give it some stability on the tall side), and 2 in the putter pocket. The storage is what starts to set it apart from the majority of the small bag market. In the tall side pocket, I can fit a large hoodie. Even with it jammed in there, I still had room for my wallet, keys, and phone. The back panel is actually separated, so you can slide a mini, scorecard, etc. in behind the dark green part. The bottle holder is plenty big enough for a 32 oz. nalgene with a little space around it to spare. If you go with just a regular water bottle, you can even tuck a towel around inside. The main flap also has a pocket in the top for a scorecard or mini.
A normal 1/2 Pack is set up for quads or a single strap. This one is built with a sling strap. I'm using it as a "prototype," if you will, for a slightly bigger sling bag built mostly with this frame in mind.
Obviously, with any No Excuses bag, you can customize your features. Add pencil pockets, dedicated mini pocket, etc. to fit how you prepare for your rounds.
I love the bag. It's really light, comfortable, and great for casual rounds. The sling strap lets me just swing it around the front, grab my putter, and tap in. Whether it's "worth it" is up to you. It would take someone who's really looking for something specific to outweigh the Crunch Box or similar small bag for cheap. This, however, will be perfect for my wife once my sling bag is finished and I use that as my casual bag.