The answer is maybe!
The Tamron 60mm f2.0 Di II Macro
is 20% longer, 2/3 stop faster and doesn't need a converter to go to 1:1, so overall it's a more convenient and slightly more versatile lens. However it's probably not going to give you noticeably sharper images then the Canon lens does when shooting at the same aperture.
Of the two, I'd take the Tamron, especially since there is a $100 rebate on it at the moment. That makes it cheaper than the Canon Lens plus the lifesize converter needed to go to 1:1 macro. Whether it's worth trading in the Canon lens for the Tamron is a decision only you can make of course.
One point to note is that the Tamron lens is designed for use on APS-C sensor cameras, while the Canon lens has full frame coverage. This may or may not matter to you. Obviously it's not a dactor with a T2i.