The poses are all stiff, most Micro-Heros are built off a small pool of body templates, and shading is generally limited to a single additional color. That's why they are hated by many serious comic nerds and precisely why I love the crap out of Micro-Heros. Like the programming magic of HeroMachine, the design ethos of Micro-Heros makes it braindead easy for normal non-artist types like me to participate in creating superhero visuals. Grab a template or one of the zillion already-made figures. Then open it up in MS Paint, hit the Zoom feature and get crackin'. YOU can make your own Micro-Hero. It's that easy. The figures are so small you can edit them one pixel at a time and it doesn't feel like superhard work.
So no more excuses as to why you don't have art for your superhero PC. Hell, there are a few sci-fi and fantasy MH's out there as well if you need help with that sort of thing. Though if you're looking for Starfleet personnel there's a cute little Star Trek paper-doll sort of thing out there that would be perfect. Damned if I can find the link right now.
But the Micro-Hero concept goes from 'dumb but cute' to 'totally insano' with the work of this guy named Razer. He does something called Byzantine style Micro-Heros. Just imagine the 1990's taking a big ol' dump on the costume of your favorite comics character: