Assuming he is on RBR's payroll (and I believe he is), he will definitely be biased towards RBR...it would be impossible not to be. My feeling is that he genuinely "likes" RBR. They have treated him well, and it is impossible for him not to view RBR without rose-tinted specs.
I personally like the combination of Crofty and Davidson. During the practise sessions, their commentary is 2nd to none. I don't understand why the BBC are clinging onto Brundle as if he is Gods Gift to commentating. If it were me, I would ask Brundle to commentate on the practise sessions and ask Croft and Davidson to do the main shows, with after show analysis with Brundle, DC, Jordan and Humphries.