I have had the two bottle model for a number of years and it has held up nicely. I was seeking a new hydration belt with more liquid capacity for longer runs. As I was extremely happy with my last belt, I did not hesitate in getting another Nathan product. I really like the swivi-buckle clasp on the belt. I find it extremely easy to put on and take off. My one complaint with regards to the belt is that in the summer when wearing lighter running clothes, despite adjusting the belt to its tightest setting, it becomes a bit loose when the bottles are full. The bottle holders on the 4 bottle model are very well designed. The bottles are nice and secure on the belt and there is no chance of having the bottles falling out on a run. The 300 ml bottle size is sufficient. Given that there are 4 bottles, this allows you to have 1.2 litres of liquid on your longer runs. The lids close well enough that there is no leaking at all. I also like that the mouth of the bottles are wide enough to accommodate standard size ice cubes in the bottle to keep your liquid cold. The bottles are also designed so that they are easy to take out of the belt and put them back in while on a run. Best of all, the bottles and caps are dishwasher safe which makes for easy cleaning. The pouch is also more than a sufficient size. It has plenty of room for car keys, gels, and any I.D. cards you would like to carry. There is also enough room for a cell phone. All in all, it is a very good product and I would recommend it to anyone seeking a good hydration belt.