Personally I would rather fly from Brum and change at where eve, than travel down to Heathrow.
I completely agree with you on this, but if you transit via a European port such as FRA or CDG you usually end up paying a lot more for the ticket. In my case coming from AMM, LHR is the only option for me until I saw the BMI webite and found it was £150 cheaper if I carried on to MAN. Don't ask me why but I've raised this in other threads and no on can give me an answer.
Shame BMI don't fly to BHX like they used to years ago.