Galorath incorporated is size metric agnostic. If it has a relationship to effort we are all for it and our SEER models can use it. Of course we dabble in new sizing methods, from Lee Fischman's evolved function points, to our function based sizing, to web page sizing. That being said, I was very impressed by the word of Roberto Meli, the creator of simple function points and Luigi Lavazzra, the professor that lead the independent verification of simple function point's ability to produce an IFPUG count more quickly.
Here is the bottom line according to Meli: