Man of Honour
I've got the 300mm as well and its a great lens but the lack of zoom can be a pain, tempted by the 1.4x but think i'd regret not jumping upto the 2x. The em5 is pretty grainy on high isos so try and avoid much over 1600 which does limit its usefulness in the evenings for wildlife.
The 150-400 looks incredible but quick a chunk of change!
The 150-400 looks incredible but quick a chunk of change!