I find that, unless there's an extremely necessary reason, it's almost always bad to break backwards compatibility. If there's any concept whatsoever of continu

I find that, unless there's an extremely necessary reason, it's almost always bad to break backwards compatibility. If there's any concept whatsoever of continuity between major releases, backwards compatibility should be the default, with changes being options. Naturally this leads to more difficulty in testing and maintenance over time. But that extra work pays for the benefit of having a very long lived product and compatibility with past integrations. At the end of the day you have to decide if you're building a product to be easier for the users, or the maintainers. Personally I'm on the side of the users.