See what changing plan does before you change it
Downgrades show exactly what would go over a limit first, and give you 30 days to sort it out rather than cutting you off.
Changing plan tells you up front what it would mean: which shows, seats or storage would be over the new limit, and what you would need to do first. If you go ahead and something is still over, you get 30 days to deal with it rather than losing access on the spot.