Is your Barretts full circumference? I think I would only want laser treatment if I had dysplasia. Barretts itself doesn't have a huge cancer risk - less than 1% of people with Barretts actually transform to adenocarcinoma. There is a thread which I'll bump up for you about Barretts - I looked at a lot of the research last year. The biggest take home point is that the biggest cause of death for people with Barretts is actually heart disease, not cancer, when you look at deaths from all causes.
I would want to know what the chances of your Barretts resolving on its own is, now that you've had the Nissen, and also what they estimate your risk of cancer is. There is a slightly higher risk for males over 60, but the people most at risk are the ones walking around without symtpoms, not having endoscopies.
I think you have to weigh it all up carefully - are you so worried about cancer that you won't sleep easy until you have ablation, or are you relaxed enough about it to just have regular endoscopies?
Just my thoughts!
New stuff: GERD, Recurrent cystitis/Overactive bladder
Lifelong stuff: Food allergies/intolerance, eczema, asthma