I love my 135L. Incredible lens! But it's not really that flexible to use. The sigma 30, I love it too, but it's time to say goodbye after I've owned 5D for 4 months now. And the 85, I just don't seem to use it much recently.
Anyway, I need to get a 70-200 2.8 lens. Shall I get a 70-200 MK II or 70-200 sigma os?
My concern is that after I"m spoiled by the PQ of 135L, will I be happy about 70-200 sigma os? I'm not pixel peeper and I'm happy about the tamron 28-75 too. Amazing lens, a big surprise to me since I've almost never heard of it before.
So anybody who has experience with the sigma 70-200 os and tamron 28-75 or Canon 70-200 f/2.8 non IS, what's your opinion on the sigma? Does it compare to the other two in terms of sharpness at 200mm, wide open at f/2.8? The tamron 28-75 at 75mm f/2.8 is excellent, the 70-200 f/2.8 non-IS Canon also makes me happy wide open at f/2.8, 200mm. If the sigma 70-200 os is comparable, then it might be a cost effective chocie, since it will save me $1100! 
I can afford 70-200 MK II and I"m more toward it right now, but if the sigma 70-200 os can make me happy, then I'll consdier that too!
Cheers!



The 20 isn't as good as 50 optically speaking, but it gives me a 32mm FOV on 60D which is important, especially for low light since I will no longer have the 30 . 

