Take a look at Jonathan Barnbrook's Priori (from Emigre) an eclectic set of display faces. It is similar to Jonathan Hoefler's Proteus Project, in the sense that a given underlying structure becomes the base for a mixture of eclectic fonts that somehow work very well together.

I'm not saying Priori and Proteus Project look similar, I'm just noticing a similarity in the approach to building the family.

Is this a fair comparison? Are there other font families that take a similar approach? What do you think?