While I'm definitely not a fan of the Sony company, all cameras and all lenses have their own quirks that a good photographer learns to deal with.
To me, one of the potential advantages of mirrorless bodies is elimination of the mirror and all the mechanical claptrap that goes with it. However, I don't want a smaller body. I'm hoping we will see a mirrorless Canon FF body that is the same larger size, uses the same EF lenses, but has no mirror to bang up and down. Its coming, but when??