I take Topamax. I like it. It really works well for me as a mood stabilizer. I even like it better because I lost 25 pounds a few months after I started taking it. I no longer binge eat like I used to.
Zyprexa is a big weight gainer. I tried it very briefly and gained 15 pounds in a few weeks. I since switched to Abilify.
I just love my Topamax. I started it almost exactly 1 year ago. I am so much more stable and I am 40 pounds lighter.