The Legendary Pixel Crew

Tower shields in Pathfinder are really nothing compared to the gamebreaker they were in D&D 3.5 edition. In 3.5, tower shields allow you to become immune to weapons, letting you walk right through entire armies. A well-designed D&D 3.5 paladin with a tower shield is basically immortal.

Pathfinder's "can't be attacked from one direction" rule is much more sensible. While it makes things more complex, it also prevents you from just crowdsurfing on cloud giants, because they can just move around your oversized shield.

That's a terrible, but unfortunately reasonable (based on the poor wording) interpretation of the 3.5 rules. It should have been worded better. Much better.
Though, it should be noted that people could just sunder the shield. You could even interpret it that if using the tower shield for total cover you can't resist the sunder attempt (Since there is an attack roll to resist, but you have to give up your attacks).

Tower shields are still the end all be all of missile defense. I mean, get yourself a divinely blessed adamantine tower ehield, and you're protected from basically every ranged weapon and many spells.

Protection from arrows only goes so far, but you can wedge your shield into the ground and brace against it to block bigger things.

Tower shields are pretty good, but tornadoes are better. Complete immunity to ranged attacks, even by siege weapons! Of course, you can't *make* ranged attacks, but that's okay.