I got my flight vest a month ago and feel like I've gotten enough use out of it to properly give it a review.
This is my vest in its ready state (minus water). It may not look like much but I've got every tool I need for any trail repairs, a decent 1st aid kit, a 70 ounce water bladder, and my SPOT beacon all balanced out in those pockets. To protect the vest from vibrating tools poking holes, I picked up some Husky tool organizer pouches from Home Depot ($10 for a 3-pack). That first picture shows the two smallest pouches. All of my tire repair items have a permanent home in my fender pack so those aren't included, however there is room if I wanted to move them to the vest.
I'll admit the vest is not light and I can definitely feel it while I'm riding, but its 1000x better than even the best backpack. I wear it over my chest protector which further helps to distribute the weight and has the added benefit of increasing airflow under the vest. Having the piece of mind that I can remove any bolt on my bike is definitely nice and this is definitely the way to go if you want to ride far from camp and be prepared to get back on your own.
-Only one pouch has any sort of tool organization and its not particularly reinforced. Using the cheap Husky bags is pretty much a requirement if you don't want your tools poking holes in this thing.
-The water bladder isn't the best. 70 ounces goes pretty fast, although there's probably room for at least a 100 ounce. Also the bite valve is kind of a pain. You have to bite way too hard and you really don't get the kind of flow that you see with many of the other bite valves. Both of these issues I consider minor since you can easily replace the bladder and/or bite valve.
All in all, I'd rate this a 9.8/10 and would highly recommend it to anyone that usually rides with a backpack. Seriously this thing is golden. Plus it costs about the same as a backpack of decent quality.