I have had a Medtronics spinal cord stimulator implant for close to 10 years. I have had my share of problems - leads slip out of place due to a bad fall, too much scar tissue built up and caused me to loose the stimulation, as well as bad infections which neccesitated them removing the whole thing for 6 months and then re-implanting it all over again - I have had round leads, flat leads, surgical leads, chargeable & non-rechargeable batteries, and because I have to have my settings as high as they go to get the relief I do, I go through batteries very quickly. I have used up a 5 - 7 year battery in as little as 2 months, and the maximum life I've gotten is 11 months, and despite all of that I would not ever want to be without it.
I got more relief out of the trial than I ever have had out of the permanent implant. I don't know if the placement was just better and they never quite got it the same or if my body has just gotten used to it and it is not quite as effective, but to me any amount of relief is worth it. There is a recovery period after the initial implant where he will have to be very careful about his movements until the leads have scarred into place, and then he should be fine to do every day activities and moderate excercise as his body and pain level will allow.
I am still in a lot of pain every day, but for me the SCS along with an intrathecal pain pump and oral meds, makes the pain tolerable most days, and I am able to be more active with it than without it. I am diabetic also and have been working at loosing weight as well, and although it has taken me a long time, I have lost 64lbs.
I hope that I have helped answer some of your questions and not confused you even more. I am just trying to be as straightforward and honest as I can be about my experience. You will find some people that have had a 100% positive experience & others who don't like it at all, that is why they do the trial. If I can answer any further questions, feel free to ask.