I had a terrible mortgage experience with BoA. Since then I will not do business with them for any reason.
There were two major issues. First, when I refinanced with a different lender, they took longer than the legally mandated 60 days to locate my cooperative apartment share certificate. This triggered lock period overage penalties of around a thousand dollars. I called BofA about this multiple times, but was repeatedly told that they would not cover those penalties. They also told me in so many words that I'd lose any battle with them, so they were pretty much free to ignore the law.
Like a true mustachian, I had been prepaying my mortgage right up to the refinance. While the refi was in progress, instead of applying the mortgage against the principle, they suddenly decided to credit them toward future payments. Effectively that meant I was lending them money interest-free. Not only that, but at the refi they didn't count those future payments towards my mortgage balance. I had quite a fight with them to recover the funds.
I nearly walked out of the refi, since the costs were way higher than I was projecting, but after calculating that I would recoup the money in two years with the new lower rate AND get away from BofA, I went through with it. Completely worthwhile.