I didn't want to review this until after I had had a chance to use it. But now I have. Almost everything about this pack I like, but first… My initial impression when I received it was, "Wow, this thing is big!" It reminded me of the old-fashioned "Fanny packs," as they are called in the US (and not called that in Great Britain, for obvious reasons LOL) that were popular in the 1980s/90s. I was surprised because I was expecting something that would be more appropriate for sports, such as trail running or at least hiking. It's also made of a non-stretchy material, like a solid sheet of nylon, and feels a bit plasticky. But, beyond that initial negative impression, I've come to like it quite a bit! Here's why: 1. While the more common mesh-style of waist pack is stretchy and breathable, turns out there's a lot of good to be said about something that doesn't stretch or "breathe." For instance, when it rains, do you really want your waist pack to be full of holes? While I haven't yet had a chance to test this in rain, I suspect it's inherently water resistant. And nearly every stretchable waist pack I've ever owned gets stretched out over time, a big problem if you are trail runner because you don't want the contents bouncing around. With this pack? Not a problem. 2. Solid, sturdy construction. I hate flimsy zippers, which are often the cause of a waist pack's early demise. These look sufficiently sturdy, they glide easy, and it got that extra cloth-like extension that makes them easy to grab and open/close. The buckle is sturdy, and is easy to snap and unsnap. Overall, it looks and feels as if this thing will last a long time. 3. In spite of the fact that it's pretty big, it's it's very flat against the body. Many waist packs can make it look like you've got a bit of a pouch, i.e. some bonus gut. Don't nobody want that! Even with my cell phone in the main pocket, this thing still fits slimly, nearly unnoticeable under my untucked shirt. 4. It doesn't jiggle when I use it, even when trail running. I've spent a lot more on waist packs designed for runners, only to find that it's hard to keep the pack secure against my body or it's hard to keep the contents from jostling about. I didn't have that problem at all with this pack. It was easy to completely forget about the fact that my cell phone and its case was in the pack. 5. It holds a lot! It's main pack is generous, able to hold most mobile phones. Mine is an older Samsung S7 (not huge, but definitely not small) with a case, and it fit easily. The big main pocket has a divider, so you can keep a couple of credit cards or cash in there as well. There are two bonus pockets on either side of the main pocket, not big enough for a man's style wallet, but plenty big enough for 3 or 4 gels or a bag of trail mix or whatever. 6. It's fit is highly adjustable, and stays in place. These can both be problematic with waist packs, to my experience. You managed to get the straps in just the right position, but then they don't hold that position. That has not been a problem at all with this one. Once he got the initial tightness set, using its straps on either side, it holds its position. All in all, I'm pleased with this purchase, and would recommend it for someone who is trail running, road running, hiking, or even just once extra pocket space while strolling through an amusement park.