Sigma 100-300 F4 vs Canon 70-200 F4

[futureal33]

Im in the market for a telephoto zoom lens, and Ive narrowed it down to these 2.

Both get near on identical MTF ratings, with the advantage leaning slightly towards the Sigma!
The Canon is an L and the Sigma is an EX - so both good quality build.
The Canon is cheaper.

Ive wanted to buy an L lens for ages, and this seems like the most affordable one... but the Sigma lens is a damn good competitor it seems!!

Id probably be pairing either lens upto a 1.4 teleconverter for extra reach - in this case, again the Sigma comes out top for that extra length..

Any advice/experience gladly appreciated!!

Thanks!

 

[tibbsey]

I'm also interested in this, when I have the money one of these (or the Sigma 70-200 f/2.8) is next on my list.

 

[squishy]

If you need range (sounds like you do) then the sigma sounds like a better choice.
I'd make sure you buy from somewhere that you can return it to if you need to though, it might be nothing but I've seen some damning reports on quality control for the 100-300.

I wouldn't expect it to be quite as sharp as the 70-200L in the comparable range, but reviews seem to say it's pretty close in the 100-200 range with not to big a drop off in quality at the top, where it out-ranges the 70-200 by quite a margin.