Going back to the original question in this thread, there is another thread running right now comparing the 24-70 f/2.8L and the 24-105 f/4.0L IS. In many respects, I think the 24-105 is probably a better lens for a serious amatuer, if for no other reason than the versatility. F/2.8 is nice to have where you want tight DOF, but only if you need it. Otherwise, for low light shooting situations, the IS on the f/4 is an excellent alternative to big glass.

