Dominick Layfieldwrote a review of CamelBak Marathoner Hydration Vest on November 30, 2015
Familiarity: I've put it through the wringer
I've used this in a bunch of ultra-running races. Executive summary: it's excellent.
I like the exposed hatch on Camelbak packs because it enables rapid refills without removing the bladder from the pack. This version covers the hatch with a couple of zippers which are pointless and somewhat annoying. Other Camelbak packs (like the Classic) just have a lightly elasticated flap that hooks over the hatch and is easier to operate. However, this is a small quibble, and everything else is great. The biggest win is that the liquid doesn't slosh around when you run. In this respect the pack is better than every other brand of hydration pack that I've ever used. The elasticated pouch at the bottom of the pack is very handy for stowing gear quickly. Pockets on the front of the pack are smallish (not designed for water bottles) but great for gels, phone etc.