I have the EM1.2 with a Pana 100-400 but I'm struggling primarily with reach for wildlife shots, as well as often disliking the background bokeh of vegetation, particularly grasses. The 300mm F4 feels really nice on the body but with the teleconverter fitted it's not much faster and has barely any more reach. I haven't had to chance to use one outside of a shop. The Sigma 150-600 Sport looks good and would give great reach but I've read somewhere it cannot work on m43 due to it's power requirements. However I have come across several youtube videos with it on Panasonic bodies ? The 4/3 300mm 2.8 is interesting as it's both faster than the Olympus f4 and also has the option of a 2x teleconverter. Most of these are way beyond my price range (as are the big Nikon and Canon primes) but I have seen one with light body marks and which is described as having light internal dust not affecting images for the same price as the 300mm F4 (2,700 euros) which I am tempted by. Has anybody got experience of these with the Em1.2, for example how does autofocus work ? The other option is to switch to full-frame or Apsc and go with the Sigma for more length (especially as I believe it can work well with a 1.4 teleconverter for about 1200mm reach on say a D500). Not something I particularly care for doing though. Any other ideas out there ?