Hi! These are the 40-150 lenses I know of: 1. 4/3 mount (not micro): Zuiko Digital 40mm-150mm f/3.5-4.5 EZ. Not CDAF-optimized. Solid. 425g. 2. 4/3 mount (not micro): Zuiko Digital 40mm-150mm f/4-5.6 ED. CDAF-optimized. 220g. 3. Micro 4/3 mount. M.Zuiko 40-150mm f/4-5.6 ED. Plastic mount. 190g. 4. Micro 4/3 mount. M.Zuiko Digital 40-150mm 1:4-5.6 ED R MSC. Plastic mount. 190g. I have none of them, and have a few questions: A. Has anyone tried more than one of these on an m43 body? On an E-M5? B. I've read that focusing on the first two is much slower than on the native pair of lenses. Is focusing much slower on #1 than on #2? C. I've read that clarity and other optical features are superior on the 43 versus the m43 lenses, and particularly superior on #1. Is this what you have seen? Cheers! Note: I have a 43 to m43 adapter, so it's not a problem that use of the first two would require one.