But the problem is that the reciprocal of focal length is actually too long a shutter speed for crop bodies. It should be 1/(focal length x crop factor). In my case, I like a bit more leeway than that, so if I were using the 24-105 I'd probably want to set 1/125th or 1/160th as minimum shutter speed in Av mode.
It's about the ability to customise the algorithm in use that matters. If anything persuades me to get a 5D3 it will probably be this ability to customise the algorithm used. In fact, what I'd like to see is something that said (in Av mode):
"Use shutter speed F1 x focal length, subject to a minimum F2 then raise ISO up to a maximum of F3 before reducing shutter speed to get correct exposure."
F1, F2 and F3 would be user settable.