I can see how this is interesting, but it seems like it would be too easy for no one to ever be happy. Employees tend to either over or under value themselves pretty strongly, and while trying to level the playing field seems like a good idea, it's just inviting confrontation if you have a mix of both (like a lot of workplaces). Combine that with the proclivity for workplace lawsuits at even a hint of discrimination (in the US) and I don't see how this could ever gain wide adoption.

I also think the idea of scheduled raises breeds a sense of complacency.