Yes. I avoid both emh, AM and PM. I prefer low crowds to high crowds and generally visit the low crowd parks. Get there early and it is great.
I dunno. This common wisdom has been touted SO much that I don't think it is true anymore. At one point yes, but now SO many guests avoid the EMH park on any given day, that it doesn't matter very much.
What matters more is if you will actually be IN the park for that hour. If you plan to go to an EMH park that opens at 8am, but don't show up until after 9pm, then you have lost out on the benefit.
A much bigger factor is always the weather. If there is a rainstorm, people will clear out. If it is very hot or cold, people will clear out.
It is also nearly always a given the MK will be crazy on holidays and Saturdays. So think about it: Folks arrive either Friday night or Saturday- they hit MK first, (And avoid MK on Sunday) then they begin their rotation: Epcot, HS, AK...then back to MK on Wednesday (most likely). Another thing to look out for is a day- non emh- where a park like AK has extended hours. If AK is open until 5all week except Friday (9-9pm) then expect it to be packed on Friday. Again, adjust your rotation accordingly.
I miss the days when Fantasmic was only held two nights a week. All I had to do was avoid MK on Sat, and HS on F! days! Then we were guaranteed low crowds! (And EMH at HS!)
But all in all...if it is not like Easter week, it may not matter all THAT much, so long as you avoid MK on Saturday.
Most folks not only hit MK FIRST, they also hit MK LAST, and what is everyone's LAST full day- yup, SATURDAY! That's why Sunday night EMH in MK I s always a must do for us.
We've done it enough times, and almost no matter what week it is, if you can hang out until/past midnight, you will be able to walk on many rides with little wait. This past JAN, MLKjr, Weekend- where afternoon crowds were crazy, we more or less walked on most attractions late at night. At HS, we had only about 15min standby to ride RNRC, then a 15min wait at TSM. At MK, we practically walked on BTMRR, PotC, HM, IaSW. During emh, we were even able to get on Pan with almost no wait. Pan is almost the only ride that ALWAYS has a wait! Go figure!