I don't find a big difference in handiness unless you start getting well into "NFA" barrel lengths, like 14" or less.

That's short enough where the shouldered gun sticks out about the same distance a handgun would with the arm extended, and when you can take it sideways through a standard sized doorway without having to angle it much.

Trouble is, when they're that short they're very "blasty", especially in closed spaces, even with full hearing protection its a shock to the system.