I purchased the best pack cause I was actually going to start running only trails. I love it and can not say enough great things about this vest. Fits great around the girls in the chest area, and the multiple position loops allow an endless variety of strap locations. The 2 large front pockets store even my large IPhone. I pack gels,food,tissue,or whatever I need to fuel the run. The 2 additional pockets up top at add additional storage. The vest pack holds 2 liters and is easy to use. It fits well in the pocket closet to ur pack and doesn’t move. The hose is secure in front and doesn’t flop around. Several adjustable straps for side and back position help to keep this baby snug. I don’t feel weighed down when the water is full and it feels Very comfortable to wear. The pocket in back wit zipper does get a little wet and from the water behind it, but i put those items in a plastic bag and I’m fine. Ties in the back loosen up to hold a jacket or long sleeve without falling out. I not only use it for trail running but I take it out for long runs on the road training for Marathon. Comes is several colors I have the grey and it’s my favorite. Seriously Best investment I ever made in a running and hydration product yet! I highly recommend this hydration vest to ANYONE RUNNING LONG TAILS OR LONG RUNS!!!