I used to have the 9-18, 12-40, 40-150 and the O25, O45 and 75. While acknowledging the superb quality of the 12-40 and 75, I wanted to reduce the size and weight of my gear. Sold the 12-40 (no replacement) and replaced the 75 with the Sigma 60. I hardly ever use the 40-150, so that goes too. Although the 45 is a great lens, I feel the gaps between the 25 and 45, and 45 and 60, are too small and am considering just selling the 45, leaving me with the 25 and the 60. A couple of steps forwards or back would seem to work. On the short end, if Olympus announce a 9mm prime, as rumoured, I would consider selling the 9-18, as I use it mostly as a 9mm prime. Again, is the gap here to the 25 too large? I should mention that I have an X100, which, in m43 terms, is a 17mm. Anyone else contemplating the steps between primes?