I'd have to say I'd definitely take the characters. We opted for Mickey & Minnie, and having a guest record our ceremony (rather than pay for a professional videographer). While it was nice to have the ceremony recorded, the truth is when we went back and watched it, we found it a little annoying to overhear certain comments and to watch us all try to line up for pictures. Our memories of the ceremony were worth more than the video.
The characters, on the other hand, were worth every penny. EVERYONE, and I mean everyone loved them! Even people who would normally scoff at them and didn't care at all about Disney wanted a picture. The characters really made the wedding what one of our guests referred to as "a once-in-a-lifetime occasion." Yes, you can see the characters in the parks and at meals, but then you only get 30 seconds and there's usually some little kid interfering. Pictures with the characters, and of your guests enjoying them, last just as long as a DVD.