I tried looking at the specs but they seem very similar, and I'm not sure which is the more powerful or feature rich chip?
Scalability is the main difference. The 270 can scale to 2 way while the 1212 can go to 1. the leading digit determines the scalability. That seems to me to be the main difference from what I can see. This is given if you were looking at the two models with similar clocks and cache. Made a little comparison chart for you click here if you want it in its own window :)