The genetics of adaptation, mutations of large effect?

Many months ago I was reviewing R.A. Fisher's The Genetical Theory of Natural Selection when I touched upon his view of the nature of adaptation, precisely, that it occurs though the substitution of mutations of small effect. This dovetails with the "gradualism" which Charles Darwin promoted, and is also the thinking that drive's Richard Dawkins conception of evolution promoted in his popular books. In contrast, in the contemporary age S.J. Gould was most closely associated with the position that mutations and evolutionary changes of a larger scale, macromutations, may play a role in adaptation (though more even heretically Gould also tended to dismiss the excessive focus on positively selected traits). Ultimately the macromutational (or more precisely non-gradualist) viewpoint has a long history, going back to Thomas Huxley, and exposited most forcefully by Richard Goldschmidt. Goldschmidt took the macromutationist to an extreme, verging on saltation via chromosomal rearrangements.