The only choice
I knew I got the right hydration system when I took it on my long weekend run in the Boulder mountains. Not only did it feel like I wasn't carrying anything, with a seemingly perfectly engineered suspension that prevents bouncing and distributes the weight perfectly, but every other runner that I saw out that day was wearing the same damn thing! I probably saw ten runners, and nine of them were wearing this vest!
I've heard the bigger version is also great, but 50oz is more than enough for me, so I chose this one.