If my HyperVector skis are my babies of my ski world, my Mountain Vesta is my baby of my running world. I love this pack a whole ton. I got it to replace my Moxy vest which was my first running vest that I got on the cheap. I chose the Mountain Vesta because I wanted a bigger litre size, I wanted two chest straps, and I wanted to be able to put two 500ml bottles on the front straps. My Mountain Vesta does all this and more with all of the extra pockets and straps around the vest. I've used this vest to do things like run the Loowit (pic to the left), skin laps up at Snoqualmie in the winter, and I use it on city runs when I am run commuting.
The couple downsides I've found with this vest is primarily in the fact that some of the pockets and straps are a little awkward to use, and I end up not using them. Particularly the little tiny ones above the water bottle holders? Maybe I am missing a use for it... Also, the pack has really great adjustability, but that can cause a bit of chaffing. Specifically their "Comfort Cinch" which is used to pull the pack into your ribs. When I get it to cinch properly, it is great and I don't even notice it is there, but it takes a bit of futzing.
Pros:
Great capacity for what I am doing right now - up to 30ish mile days with crampons and ice axe along with layers
Generally really comfortable
Pockets everywhere!
Pack straps down when not filled up, so it stays tight to the body
Cons:
"Comfort Cinch" takes a bit of futzing sometimes