I have had the VNS implant for a little over a year and I can't tell you just how much better my life has been as a result of it. I went from having 4-5 grand mal seizures a week, to maybe 4-5 a year.
The Cyberonics website is a great place to get some initial info (www.vnstherapy.com), but feel free to ask me any questions about my personal experience.
Good luck and please don't hesitate to ask anything at all!