eribeiro:
When shopping for an L lens. Consider the prime EF 200mm f2.8. It's way cheaper than the 300 or 400. The reviews I read by some people say it is much sharper than the zooms (i.e. 70-200 and 100-400). It doesn't have the image stabilization (IS) but because it's a fast lens (2.8), you can use faster shutter speeds to avoid shake. I just purchased one (pick up Friday). If you want, I'll let you know how it its. It is also compatible with both the 1.4 and 2.0 TC.