Im looking to pick up a macro lense here pretty soon and its running between the Tamron 90mm and the Canon 100mm. THey seem to rate pretty close to one another with the Canon maybe a hair better. The Tamrons a little cheaper and it comes with a lense hood. The Canons more expensive and youve got to purchase the hood separate from the lense, a $45 deal. I think thats a pretty petty thing for Canon to sell apart from the lense. My question is, will there be a big noticable difference in the 10mm difference between the two? If not, other than resale value, I cannt see spending the added cost of the Canon.