I have the Neuropace RNS, I was part of the pivotal trial. I had to go in yesterday for a replacement in fact, as the battery was dying. I do believe it has helped mine some, which is actually good as I have yet to ever find a medicine that has worked for more than a year. The implant has cut down a large abount of my epileptiform waves.
The people from neuropace have been great about everything, as I was one of their 191 guinea pigs. I do have to say that it is very tough, but I think most people have had even more luck than me. I am actually waiting on my records from the epilepsy center to see how much of an improvement I have had. I had it initially put in in February of 2009.
http://www.neuropace.com/trials/overview.html
Unfortunately it is currently closed to enrollment and we are now going through the long term trials to see what the effects are over time. I do believe that it will be a big breakthrough for a number of people as many of us are nonsurgical candidates.
It is a little painful for the week after, but if you can endure it it may just be worth it.