Love this bottle. I purchased this for my husband as a gift. I had the older version without the insulator sleeve and liked it quite well. But I prefer this model and now use it in lieu of mine when we don't run together. The sleeve prevents the bottle from slipping around my hand on long runs when I start to sweat. My only complaint is it takes a hard hit to get the nipple down completely. If I don't want 'whack' it, it seems to leak. Perfect for half marathons and long runs but I typically have to refill it at a water station around mile 10.

I am a marathoner and for my shorter runs, this handheld bottle is what I always use. I tried a competitor's bottle that held a bit more, but the slim design of this one can't be beat. The competitor's model, which is like holding a large cup in your hand, was unbelievably uncomfortable. For someone who has has operations for Carpal Tunnel Syndrome, comfort is a MUST! I've ran up to 11 miles with this and have never experienced discomfort. The pocket is great for storage and the wrap is certainly nice so your sweaty palm isn't against the bottle on the entire run.

The valve on this handheld is very difficult to open and close. Requires a strong grip, which is difficult if your hands are sweaty. Also, the lid often appears to be secured and properly threaded, only to find that the liquid leaks in large quantities on first use. The harness can interfere with the seal on the lid, requiring the user to stop running and rethread the lid while trying to keep the harness out of the way. I also purchased a Nathan, and found that to be much easier to use.