I've been using an earlier model of this one for several years.
The earlier model has somewhat different stablizer straps on the sides (by the water bottle carriers) that I actually use to carry a second flyrod, which angles back and upward on my left side. Works great in open areas and while wading where you want to have a second rod handy rigged with something different, but have to take it out in brushy areas. I also installed a magnetic release on the shoulder strap for carrying my net, which I've found very handy as well. There are two models now with different capacities to choose from, but can't tell how well the second-rod carrying feature I use will still work with them or not. I carry 8 or so fly boxes in mine, so it has good capacity for fly fishing, not so sure how it would be for volume of spin tackle, however. JAX has them if you happen to be up in the Loveland or FC area.