Just wondering if any Canon shooters have any experience with the Tamron 17-50/2.8 lens. Been thinking about switching to an XT and purchasing that in lieu of the kit lens. Yes, it costs 3x as much, but the kit lens does not seem to get very good reviews (not sharp). Thoughts on that lens? Example pictures? Suggestions for an alternative lens? I guess if you have any thoughts about the kit lens, I will listen to those, as well. Danke!