[Klaus]

That 100-400mm looks pretty neat (weight/size/MTF chart) too. Not as heavy breather (widening FOV towards MFD) as the Canon EF 70-300mm f4-5.6 L IS USM for instance, with :

 

1.6m MFD, 1:3.8 = 0.26x magnification at 400mm setting. 

 

For (my) comparison, my Canon EF 70-200mm f4 L USM gets 0.21x at 1.2m, the EF 70-300mm f4-5.6 L IS USM gets 0.21 at 1.2m also.

 

With its relative low weight and possibly nice price, it might just be a lens for me in future.

 

It's still heavier than 1Kg. In the good ol days, there was the Minolta 100-400mm with just 840g.

The MTFs are looking decent though.