There were things I liked about Hopville, but Brewtoad had some functions I preferred so I made the switch a year ago anyway. Really these are just basic recipe calculation sites, and the hopville water calculator was way off for my system anyway (I have created my own Excel spreadsheet for my systems water anyway).
I am kind of hoping Brewtoad picks up on some of the things I preferred about Hopville, then it is best of both worlds. My spreadsheet gives me most of what I need anyway, the site just gives me a place to store my good recipes and ideas I am working on.