You've just lost all credit in the discussion by claiming that BF series is anything like BC2.
They're all better than CoD for that matter but that doesn't make them the same.
Also, BF3 will use a different engine to both BFBC2 and BF2.
I think you've just lost yours by saying Battlefield games are all better than CoD. Works both ways right?
Also, BF3 is on the same engine as BC2, just a more improved "next generation" one!