My 400-350 NE double has a set of 26 inch 20 g barrels with screw in chokes and while I don't fit the shottie tubes all that often I do like having the option.

It was a shotgun to start with and the rifle barrels were custom made to ballance right without changing the original weight of the action or butstock.
This setup means that no matter whether the rifle barrels or the shottie barrels are fitted, the ballance still feels right with either barrel set.