My thinking used to be much like yours - IS only matters on long lenses. While I still feel that is where it shines, I have started to see differences between my A7R and my 5D series cameras. The one point is IS still doesn't help if you are shooting kids - you have to have fast shutters. But aside from that, it really is a big help. I get a lot more sharp "keepers" from my Sony body with IBIS than with my 5D4 without. And this is with the same glass - 50L, 85L, 24-70, etc. So having a 50/1.2 IS and a 85/1.2 IS is VERY cool.