I use this bag every time I go to the gym and it is amazing! There is a front pocket with felt lining on the inside to protect your small items from what might be in the sack (wet clothes, etc). There are two "pockets" to store water bottles, but they go inside rather than a separate pouch outside. They can fit big bottles though; I put my 16oz hydro flask in for comparison and there's a ton of space left still.

The material is very durable and you can fit more than you think. When I go to the gym, I just place my small items + maybe a change of clothes in the bag. I've also managed to stuff a weekend's worth of sleepover clothes/makeup/toiletries in there too! Overall a great bang for your buck!