I have been an x-pro1 user for a few years. I have the 35mm 1.4 and 14mm lenses. I also have an old canon 50d and a 400mm 5.6 lens for wildlife photography. I have been considering getting an x-t2 and the 100-400. It would be nice to have two cameras that share lenses and the smaller footprint of the x-t2 versus the canon. I have been trying to get definitive answers on how good the x-t2 is for bird photography but it seems there are a lot of conflicting reviews of the AF and other factors versus a dslr. Being that I already have the canon lens I could upgrade to something like the 7d. It sounds like it may be a better camera for bird photography and it would be a cheaper upgrade although offset somewhat by selling the canon gear.