I don't have problems generating enough enmity or holding hate, but if you have some BLMs who are worth their salt and go full out, you won't be able to stand there for 1-2 minutes and do nothing.
Tank swaps are easy too if you build up combo before provoking and if the other tank doesn't spam hate combo after swap.
Generating enough enmity on a single target is not hard at all, but keeping 5+ mobs on you while DDs go crazy with AoE damage, leaves you no alternative to Flash and Riot Blade spam.
I don't want to make PLD a better tank, I'd like to have a bit more variety than Flash+RB or 1-2-3.
As some already said, there is not much you can do to stand out of the crowd of average PLDs.