Since I have been increasing the distance of my runs and I sweat a lot I had to get a hydration method.  The heat retention of a camelbak would be too much so that was out, and after reading the reviews of the larger bottle holders I decided to get the Nathan Speed 2. It was the right call.
I wear a size 30 waist jeans and I ordered the small based on that. With two full bottles the belt moved not a bit.  Not a wiggle not a jiggle.  The bottle spouts are soft so there is no fear of bumping lips or teeth while running. The angle of the bottle neck makes allows the water to flow without having to turn it completely upside down.
I like the room to store my car keys and what not.
I am VERY pleased that I bought this item. I would definitely recommend it to anyone who is looking for some hydration during runs.

This belt is lightweight and comfortable, the adjustable velcro strap makes sure that it stays just where I put it. The poket in the back is big enough to hold my key, smart phone and 2 gel packs. It is easy to get the bottles in and out witout the worry of them falling out or slowing me down!

the design and fit are perfect for me- a petite, short female. the belt is snug so no movement and very comfortable, The bottles are a good size- they hold enough for hydration but don't make me feel weighed-down.

Great belt that allows me to go on longer runs. Also, great for family hikes.