I was on C from 2006 until 2010. I did get new lesions and had a series of flares. This was within the first 2 years. After that, my brain MRIs have stayed the same. I haven't had an MRI in a little over a year so I don't know.
Also, I still got flares even on C. They just weren't as intense and didn't last as long. That was the only difference I noticed.
Getting a 2nd opinion may be worth it. It doesn't sound like this neuro is willing to work with you. In other words, he sounds like a "It's my way or hit the highway" kind of neuro.
Let us know how things work out for you guys.