I have or have used both. Bought a divide 1500 last fall, played around with it a little, and returned it. If you put a full 3L bladder in it, there wasn't much extra room in the main pocket for anything else. I also like to strap my bow to my pack while hiking, and there were no straps for that and I couldnt find a way to attach straps to hold my bow that I liked either. I liked that you could just stuff a hoody into the center part, but that was about the only part of the pack I liked.
I now have the venture 1800 (tried the 2300, but had a couple things I didnt like about it as well), and have only got to play around with it a little, but so far I like it. Easily fit a full bladder, kill kit, game bags, possibles pouch, rain jacket, hoody, and lunch in the main pocket, and odds and ends stuff in the other pockets. I like the straps on the outside (just wish they were 3/4" rather than 1/2") and you can move them around on the daisy chain webbing depending on where you want them.