Apologies for opening a new thread on this but going round in circles. I'm looking to replace my current set up (7d Mark ii, Canon 100-400 ii) as it's getting a bit heavy for me. I'm mostly a birder but like taking pics. I mostly use the camera for gulling at the moment but also do a lot of coastal birding so want a sufficiently fast set-up to enable (record) shots of any goodies lurking in the bushes/woods. After going round across the multitude of options I'm considering the Olympus OM-1 with the Panasonic Leica 100-400. This seems to be an attractive option both on weight and performance. I realize that it will be a step back on the glass. Does anyone use the combination? Not looking to move away from versatile zoom lens.