I haven't read enough of the comics to know what Mikey is like...but I do love his portrayal in the first three movies.
I hate how he is in the new toon, because they turned him into an idiot who's always goofing off and getting himself into trouble. He's ALWAYS the "damsel-in-distress", he's always the one who has to learn some sort of stupid lesson, half the eps that center on him sucked: The Turtle Titan, the Notes of the Underground arc, Grudge Match (that ep only got good in the end when he totally kicks ass, but sadly...like Touch and Go...he doesn't stick to his learned lesson and quickly reverts back to the way he was before.)
Mikey started off good in the new toon, but he really started getting on my nerves (even though I still love him) at the end of season 2 (I hated the Big Brawl).
I hope this upcoming movie writes Mikey as he was in the comics and the first three movies. That's the Mikey I love.