Pros?
Can have a gorgeous tank and don't look tacky with fake plants. They will eat up nitrates, add natural element to the tank, provide great hiding places for fish. Lots of creativity can be thrown into the tank.
Cons?
Can take a LOT of work, can be expensive, requires lots of research, limits the types of fish you can have.
Probably more to add to the list, but I would encourage you to do it. It's just another step in fish keeping and can be a great project.