I prefer using the
BPR to statistically monitor driver performances:
http://bprf1.com/2010/04/05/bpr-upda...an-grand-prix/
Joking aside, through three races I think the only cases of 'out-performance' between teammates are at Mercedes, Renault, and Williams. That being said, it's still way too early to draw any meaningful conclusions...
This will make for an interesting topic over the course of the year due to the driver pairings!