PLO is higher variance as equities run closer, so having a tough mental game is important to handle the swings. Probably many bluff opportunities in both games, being balanced is important in both, but with more cards, could ranges be wider in PLO, thus making it harder to put your opponents on a hand?
But then again there's more you can do with that information in PLO, thus making it more complex.
This topic came up at my 5/T game a while ago and I've been thinking about it on and off - is hold 'em harder than PLO? You have more information in PLO since you have more cards, and less info in hold 'em, which makes me think hold 'em is harder.
