The guys behind Gumby framework have added the hybrid (12+16 columns) grid.
Which means on the same page you can have the 2 systems that cohabit at the same time.
What about the the design homogeneity? Do you think merging both systems into 1 hybrid is going to decrease/break the visual appealing/structure of a website/webapp?
FYI here is the philosophy behind gumby framework