We usually don't do anything shorter than a 14 night...but opted to do a very unusual (for us) 4 night out of PC just last month.
Three reasons...20 minutes to the port from home. Had never been on Allure before. Wanted to see Mamma Mia while we still could.
Nice little fill in cruise, enjoyed Allure, but totally bummed that all Mamma Mia shows were cancelled.
Oh well, adding to RCL coffers. 😉 And even a little 50 PC stock bonus to enjoy while on board.