The aesthetic appeal of steampunk is hard to deny: the shiny brass, the distressed leather, the visible gears; it's all pretty sexy stuff.
The literary style, though, has much less to recommend it. By setting their stories in a colonial era, many steampunk authors end up avoiding any real interrogation of contemporary societal relations. It's easy, frankly, to condemn the Satanic mills that dominate the parts of steampunk not consisting of waiting for the dirigible in some foreign land. It's harder to take on the question of civil rights in an increasingly corporatized society.
Cherie Priest's Boneshaker is not the most egregious example of steampunk I've read. It's set not in a colonial land, but in Seattle, during an extended US civil war. A mad scientist lets loose a poisonous, zombigenic gas that quickly renders the central part of town uninhabitable except by the desperate and the undead. The town throws up a wall around the afflicted district, and abandons it to the gas.
Fifteen years later, the scientist's son sneaks into the walled off area to prove his grandfather a hero. His reluctant mother follows him in to save his life.
A well-drawn world, but basically a zombie story. I'm interested in reading more by Priest, but I won't remember this book for much more than the atmospherics for too long.