Try using the outer pocket next to the bottle holder. It big enough to fit another water bottle. For counter ballance I just put all my personel stuff in the sub pouch next to the putter. Ya, I also put my Innova soft divider in instead of the standard one. I love the bag.
Latitude 64, It easily holds 14 discs with the divider that it comes with, but with a few of the velcro dividers in it it can easily hold 30. With tons of room for all the extras. Shirts, towels, water, it has storage for just about anything.
Revolution bags are indeed great and last a long time... but they are expensive obviously.
I had an Innova bag that didn't last me very long.
I've gotten through two years of heavy play with a Revolution Dual Pack and it still has plenty of years of heavy play left in it! On occasions where I don't need many discs, I'll use my Revolution Mini Bag. I picked up a Revolution Carolina Bag at a tourney in Ohio (as an award), and love it (although I have yet to use it for a round since I'm waiting on the internal frame to arrive). The Mini and the Dual Pack have been great in the two years that I have had them. Dual Pack always leaves me with plenty of room to hold a stool and umbrella. I can even throw in a light jacket. I got it for the extra space and I love it. If you can afford it, Revolution is the way to go!