A friend of mine asked if I want him to do a firmware update on my Gazelle Ultimate C380+. I last time I had that bike at my local bike shop, they didn't say anything about a firmware update. Does anybody happen to know what the updates are?
Ask your friend. Previous-gen Bosch motors used by C380+ doesn't have user-updateable firmware and requires Bosch-authorized dealer with special software to do that. If your friend happen to have one, he should know the changelog as well.