The first half of the movies pretty great. Pretty much until the get out of the deadlands or whatever it is.
It also loots from Terry Gilliam films extensively, especially Time Bandits and Baron Munchausen. That is sort of awesome and sort of lame. But,hey, if you are going to loot surreal fantasy from someone, Gilliam is a good choice to do it from.
Depp recently said in regards to Pirates 4, "At this point I'm trying to turn it into a Beckett play."