I am buying alot of stuff in a day or two. 20D grip, flash bracket, etc... But the big item is the 70-200 2.8 IS. I want to get a 1.4 teleconverter also. I used to have the cheaper $109 Tamron 1.4. I was not too happy with the results, so I sold it cheap. I hope the new converter will give better results. My small dillema is, that I hope to get the Sigma 120-300 within a year or two. Which converter should I get, the Canon 1.4 for $279 or the Sigma for $169?

First, will both work with both lenses? Second, is the Canon worth the extra $100

i can only speak on the 1.4x on the 70-200 IS. there is a littel bit of performance dropoff with the TC. however, with that said, if you are printing shots within normal sizes you would be hard pressed to notice the difference. i certainly do not hesitate to throw the TC on when i need it.

Sigma should work on both. And if I remember correctly, the Canon also works with the Sigma 120-300, but not with all the Sigmas that accept Sigma TCs. But it's better to ask the store if it works.. Or someone here may know it.

Any thoughts on quality difference? picture wise...