Pat,
I was on Topamax for about a year, with iffy results in the end (combined with the Paxil CR over time, I had a 4-month major manic episode. But, I think it was because I had a ducky doctor.

)
When I first started the Topamax, it did wonderfully balancing my moods, with minimal weight gain (10-15 lbs) even through titration and I didn't have any side effects. Depakote made me gain A LOT of weight and I was eventually tapered off of it totally, at my (rather demanding LOL) request.
Topamax is a great med, but it just doesn't mix with my Lithium, so I was taken off of it and had it replaced with Seroquel, which is also great at balancing moods with proper titration, and I haven't experienced any weight gain.
Geez, I think I just babbled my way through that one
Hope it helps!
Dolfin