Carrying a heavy water bottle around would be the last thing I'd want to do on a trip so I find the water bottle pocket troublesome.
I've often wondered out-loud on these very fora what all this obsession is with schlepping water bottles around. Lip balm, too, come to think of it.
I must admit I have carried one or two espressos in the center pocket of my co-pilot. However, I normally use it for various cables that would otherwise get tangled up with everything. I also use it to stuff a large Toddy Cloth (Mobile Device Screen Cleaner | Microfiber Cleaning Cloth | Toddy Gear) for the cleaning of my iPad and iPhone screens, as well as my iGlasses. Easy-in, easy-out.