I quite enjoyed this April Fool's Day edition puzzle. It was a little tougher than a usual Monday, because of all the "Fool" clues. I think there were eleven in all, my favorite of which is probably DUNDERHEAD (18A: Fool), just because it's such a ridiculous word.
As for the regular clues, we had Deco for 5D: 1910s-'20s art movement, which screwed things up for a while in the North. I thought EMEER seemed plausible for 15A: Mideast potentate: Var., because aren't emir, emeer, and ameer all valid variants? Anyway, EoSTASIA (21A: Area including China, Korea and Japan), finally told me that things weren't quite right, so DADA, the art movement had to be.
Nice to see Jack BENNY (64A: Comic Jack of old radio and TV) in there, and I liked IRONMASK, INCISOR, and SVELTE. Didn't particularly love NONROMAN even though it definitely is 50A: Like the Cyrillic and Hebrew alphabets, it just didn't seem all that great. Why not say, Like every great conquering civilization after 600AD? Blah. And EARLAP?? Again? What the hell? I feel Will Shortz is trying to legitimize it by including it once a week! But I don't say the whole puzzle is bad because of a couple, less-than-perfectly-acceptable-to-me clue/answer pairs. On the contrary, I thought it was overall a good, enjoyable puzzle. Especially for a Monday, and that's no joke!