Hi,
I am looking at buying a super telephoto and I have narrowed the choice between these two option:

EF 300 f/2.8 L IS II with 1.4x --> plus = fast, sharp, better IS / minus = price, weight
EF 400 f/4 L DO --> plus = light / minus = old, low contrast, optical quality

I know that the contrast and quality can be taken up a notch in Post processing for the EF 400 and that the light weight is very interesting but the sharpness, better IS and the versatility of the EF 300 package with the extender is interesting too.

Can anyone share their toughts on these choices? Mostly about the EF 400 DO. I'm looking into renting one to experience the lens for myself.

Right now I am leaning toward the EF 300 combo or should I wait to see if the EF 400 F/4 L IS comes true?

I also already own an EF 70-200 f/2.8L and a EF 2x

Thanks,

Andre