altimeter setting
If I may interject I would like to profer my opinion? As an RAF pilot with 14 years FJ experience I can see both sides of the argument. In the UK I would much rather use QFE because it is easier in my mind. I am currently based in Canada and in the last year have flown approaches into Boulder CO, Great Falls MT, Casper WY, Salt-lake City UT (I'll stop there or it just looks like bragging) and QFE would make absolutely no sense whatsoever (as discussed here it would be far outside the range of pretty much every altimeter on the market).
In my experience UK civvy airports will give QNH unless you ask for QFE. This arrangement works just fine for me and appears to be the best of both worlds.
I am pretty happy with either. I think the maths that Dave Wilson may be talking about is the need to add circuit height or DH to runway elevation.
BV