Am seriously considering a macro lens (Uncle Sam's rebate needs to go back into the economy) and am trying to understand differences between these two lenses. Focus capabilities aside, the issue I am curious about is the 1x (EF) vs 1-5x (MP-E). For insects (including aquatic macroinvertebrates apx. 5 - 15 mm), flowers, various small 'found' photo opportunities. Is the 1x enough? What are the advantages / disadvantages of going with the 1-5x MP-E?