Felt the same when I tried it out a month ago, really amazing lens.
How heavy is it? How long can you hold it?
When I tried it last March at Focus on Imaging, it felt similar in weight to the MkI version of the 300 f/2.8 L IS, but it could have been down to better balance on the 1D IV it was attached to also.How heavy is it? How long can you hold it?
It's not that heavy at all. I was quite surprised when I held it that it felt quite good with the weight. No problem hand-holding it for me, even though my techniqes was not the very best for the quick shooting that I did