My only problem with Howard is that he's not that good. Yeah, the dude can fill up a stat sheet, but there are caveats with all of those things: yeah, he gets a lot of rebounds, but he's always been on terrible rebounding teams on which he's the only big guy on the floor (Rashard Lewis is the Magic's "power" forward!). He scores some points, but besides the slam dunk, he's got no identifiable offensive weapon or creative move that will get him a basket when his team needs them; it's all good passes from his teammates and putbacks, which are possible because of his incredible combination of size, speed, and athleticism. He blocks a lot of shots, but I wouldn't call him a particularly good one-on-one defender.
I hesitate to call him overrated, but, well, he is. Which is more of about the media types that love to praise him rather than anything he fails to do. On the other hand, unlike other great players, he doesn't seem to really ever work on his game or add new facets. Why doesn't he have a decent jump-hook, for instance? Why can't he consistently hit the 8-12 footer? Very limited player. Contra what people said about him his first few years in the league, he's the anti-Tim Duncan.