Finally a vest that fits but with a major design flaw

I recently tried a different vest from another company with no luck. It didn’t fit right. After researching again for a vest, I purchased the Nathan Pinnacle 4 Liter Hydration Race Vest. This is 4L vest that has capable of holding 2 600mL flasks upfront. I’ll go over my likes and dislikes for this pack
Fit
The two straps in the front of the vest are very comfortable to me. I’m can move them up or down to adjust the as needed. The arm holes are large enough but no chaffing issues. The shoulder straps are nice as well that sit on the shoulders with minimal bounce
Pockets
There are just enough pockets to hold my stuff for running. Starting at the front, there are 2 flask pockets. This is my main issue with the vests. Other brands of packs have a little bungie to hold the flask whereas Nathan has nothing. What happens after a while is the bottle start to slip down in your pocket. It’s not a deal breaker but it’s something to note if that type of thing bothers you. There a 2 zip pockets that can store stuff so it’s doesn’t get as wet. I see people put their phones but I don’t like my there.
In front of the flask pockets are 2 little pockets, these can hold gels or salt tabs. I wish there were a little bigger or include a strap to tie it down. Down on the bottom are little side pockets that can salt tabs or trash. These pockets are nice and felt secure while running. One of the unique pockets is the pass through pocket on the back for trekking poles. I don’t have trekking poles but this could be useful for a lightweight jacket. On the back of the pack is another little pocket and this is where I like to put my phone. It sits a little higher on the back so it doesn’t bounce around. And the last pocket on the back closest to the back is the main storage. This big pocket can hold whatever you need for you long adventure.

Quality
I have this vest for about a month and took it out on a few different runs so far. The straps feel strong and will stay close. The fabric feels good to the touch. The 2 concerns I have are the zippers and the velcro. The last Nathan vest I owned the zipper was the first to stop working. The salt and sweat rusted it out and the zipper broke and stop working. The velcro on the old vest overtime didn’t want to affix. Dust and dirt collected and then it became useless for the velcro.
Overall Impression
My overall impression for this vest is I am enjoying it so far. The bottles slipping down while running is an issue. I think the vest will hold for many miles but I’m not so certain that I can get past the bottle issue. It’s a simple design fix and not sure why Nathan hasn’t implemented similar to other brands.