Very close in many aspects, but I will buy the Oly based on:
Choose the Olympus 100-400mm if:
you want better sharpness at the fastest apertures
you want better optical stabilisation when using an Olympus body
you want to use the teleconverters to get extra reach
New firmware update that would seem to provide dual 3-axis stabilization instead of 2-axis from just OIS. The comments section from the review above suggests that the new firmware was not used so stabilization will be better than was tested.
"Possible to use focus stacking photography with M.Zuikio Digital ED 100-400mm F5.0-6.3 IS.
Image stabilization performance when using "M.ZUIKO DIGITAL ED 100-400mm F5.0-6.3 IS" has been improved.
Roll compensation is available with the image stabilization function of the body, along with the pitch and yaw image stabilization function of the lens.
The "M.ZUIKO DIGITAL ED 100-400mm F5.0-6.3 IS" is not compatible with 5-axis Sync IS."
