Olympus f4 300 or Panasonic 100-400?

Sorry If I am reinventing a thread - I did look  but couldn't find a recent one.

I will decide on one of these when I see side by side tests.

Has anyone seen one? Has there been such a test yet? I suspect both companies are letting their pros try them and report back but neither company is maybe brave enough to each give their lens to the same pro!

Anyhow I can see advantages and limitations in both lenses. Wielding a 300 as apposed to a zoom does have limitations, a zoom might be more practicable but I suppose it might boil down to the quality but that will only be at 300 between the two as a key edge.

I would be interested to see other's opinions.

and really sorry if this is reinventing an old thread!