I agree with the other posters, each and every situation is different, and only the doc's looking at the specific case can give you a reasonable answer.
That having been said, I had surgery to correct a herniated disc in my neck several years ago, C4 I believe. (Maybe C5, can't remember.) They didn't fuse it in my case, as they often do, which I believe has worked out better for me given the descriptions I've heard from others. They did, however, find several bone spurs that didn't appear on the MRI's, which compliated the surgery and recovery a bit. Still, my guys did a great job, and I was back at work within 4 weeks (too early, but I forced the issue due to leave of absense issues with work at the time) and back doing pretty much anything I wanted within 6 months or so.
It has acted up on me a bit over the years, but it is usually related to some other issue, mainly stress. I consider it a "complete" recovery, though I expect I will be able to "feel" it occasionally the rest of my days.
Best of luck for your friend.