Camelbak™ has been the best for me by far. I've only been geocaching for a few months, but I've been hiking for years. I've found a 2 ltr to be quite sufficient for me. If there is a trip that requires more water than that, then a Sweetwater™ portable filter is much lighter than extra water (as long as there is water available). I use a camelbak pack that holds a days worth of snacks, smalll first aid kit, small jacket, flashlight, geocaching tools, don't forget TP!
This is the system that works best for me! As you go, you'll figure out what works best for you. Good luck!