70-200f2.8 +2xTC vs 135-400f5.6 dilemma..

Oh yeah, I myself have Canon's 2x tc. I mean its not crap, but you will lose out in AF speed and quality will be pushed at times.

http://img.photobucket​.com …yPhotography/CR​W_6600.jpg
With my 2x. Was happy with it.

True,

But its probably not good value in either pounds money or pounds weight to have a 70-200 2.8 and a 100-300 F4 or something similar in the same bag at the same time.... as tempting as it sounds!

Oh yeah, of course, but if you know what you are going to shoot, that's kinda how it would work.

Like I plan to get Sigma's 120-300 2.8, even though I have the 70-200 IS for the longer sports because i get an affordable 300 2.8. I would carry my 70-200 in my bag all the time and only bring the Sigma when I know I will need range for somethign like football, soccer for example.

grego,

I think we are talking the same language.. I still intend at some point to get a 70-200 2.8 but won;t lose the 100-300 and a 1.4 or 2x TC give flexibility for the time you pack the wrong bag...