Right now my longest lens on my DSLR is 250 (FF=400) Sometimes I wish it was longer, but due to weight issues, it's what I'm stuck with. With switching to M43 (ideally the OMD if they're ever going to be in stock again at adorama) from what I'm reading here and other places is that they're not really good with birds as the AF isn't quite there yet. The AF on my DSLR lens stinks. It's not bad but it's no where near as reliable as other heavier lenses I used to use. I also shoot gardens with the longer lens as well. I love shooting flowers and bugs etc... With weight being a huge issue for me (the main reason of this switch) what tele would you guys recommend? I'm kind of looking into the 40-150/140 the 100-300 and any others you may like. I do worry about the weight of the 100-300 as it's 5ozs heavier then my 55-250, but I worry the 150 will be too short. I also am wondering what kind of priority this lens will have in my bag as these cameras aren't great for birds. So would the 150 be enough then?