I recently got the Endure and have used it for a few weeks, including a 50 mile race this week. Here is my summary of pros and cons, with more detail below:
• Comfortable- essentially no bounce when properly adjusted, with balanced weight.
• Well-designed storage with front pocket that is easily accessible and fits a smartphone well, and a back mesh pocket that holds extra gear.
• Good value for the price.
• Like other waist-packs of similar design, gives the option of two different drinks.
• I find the valve on the 10 oz bottles difficult to close, and fairly low flow.
• Bottles are a little tricky to get back in the holster.
I bought this to provide an option of two bottles for different fluids on long races where I want water and electrolyte drinks. This was the lightest weight option I could find. Overall, this is a well-designed pack, with attention to lightweight design and practical features. The major pitfall of the pack for me is the bottles- specifically the valve. This was somewhat surprising to me as UD clearly pays attention to the ease of use with valves on other bottles- like the kicker valve. Opening it takes a little pull, but I did not find this too hard. The problem for me is closing the valve. Pushing it closed with my mouth takes enough pressure I would be worried about breaking a tooth- especially if I jarred the bottle while running. With a thumb, I can definitely close it, but this takes some attention while running- and more than light pressure. I usually make little of claims of high flow valves as I have had little trouble getting enough fluid from any bottle/hydration pack in the past. These bottles are enough to convince me you really can have a valve with annoyingly low fluid flow. It’s workable- you can get liquids through the valve. But using it along with a handheld during the hotter parts of the day, I found myself using these bottles mainly when I was walking the steeper uphills and I could afford to play around with the valve and be patient with the slow fluid flow. I haven’t seen other people complain about this so it may not bother other people- but I am not eager to use this in a race when I want to be able to drink quickly on the run. Getting the bottles back into the holster also took a little bit of fiddling on the run- not a big problem, but more difficult for me to manage than waistpacks for 20 oz bottles. Overall, this is a good waistpack if you are looking for something with two bottles and limited weight- but bottle valves really need some fine-tuning in my opinion.