Having made both, my thoughts are this:
Med: it will all depend on the port calls and the time of year.
Palma, Cannes, Nice in the summer is quite spectacular from an eyeball candy point of view. In the winter, pretty tame.
If you hit Naples, Palermo, Brindisi, or similar places, okay for history and sightseeing, or a side trip to Rome, but the fun factor is low.
The trains can get you a lot of neat places in a short amount of time, so seeing Europe the cheap way is pretty good.
Not sure if the boats are pulling into Haifa, Israel any longer, but that is a great port.
Workups may take you to the Caribbean, thought he shutdown of the Puerto Rican op area has probably minimized that.
Westpac: Almost all ports have something going for them: Kind of like "ports gone wild: the Navy edition."
Hawaii, Singapore, Thailand, Hong Kong, Australia, Japan: there's something for everyone.
Unfortunately, there is no more Subic Bay/Cubi Point/Olangapo, nor can I think of a port call that rivals it (yes, even considering Thailand). Hpwever, the others offer plenty of exotic flavors that can't be described.
Here's an interesting thought. You can catch a flight to Europe and tour most countries on a Europass (train) pretty inexpensively and in a short amount of time. Touring the Westpac countries and ports will cost you a king's ransom if you were to try and do it over a 2-4 week period, so the Navy may indeed provide a travel opportunity you won't have available as a civilian.
