As a complete beginner...
I just skipped to the end ones just to see if they'd be any challenge, and i was pretty right and assuming they weren't.
"Academy" is wrongly used here. Sure, they might be fun to play for beginners. However, if you want to get better, IMHO, play really hard songs, or at least ones out of your reach. I always play insane charts even though i just started...and my accuracy has improved over 10% in the week or two i've been playing(no, i don't play 24\7.)
If someone played insane charts for 100 hours versus someone playing easy-med charts for 100 hours starting out, who do you think would be better at playing higher difficulty charts?
The beginner couldn't even begin to sightread(which is my main problem in playing if i can add - i can stream\follow just fine, i can't read the charts well yet though(Meh, my eyes are terrible to go with this too though sadface. Could probably consider me nearly blind in the only one i can use...))
The begginer might have improved a bit, but he wouldn't be able to play at the higher speeds either. Assuming the expert player practiced intelligently, he should be more skillful than the beginner, although it's only 100 hours time.
That's my take on it at least. At least start on hard+ charts(bad apple was a nice starter for me, cirno's perfect math class is hell but was my first map. playing something that's almost out of your reach isn't something i've really tested much yet - may later on...) and you'll be better than sticking with what you're good at.
EDIT: also the miku - this is sparta map is pretty badly timed...and i hear the others are as well...that's just misleading the beginners even more....shouldn't even be ranked.
SECOND EDIT: Oh yeah, one more thing. Get used to playing AR10, good way to increase your accuracy on your hardest maps in an hour lol..(for me at least xD)