I am a zoom man. I frame the shot. They are slow. I see the need for a fast prime. My Olympus 60mm f2.8 macro is really used for macro. I was getting slow shutter speeds using it handheld yesterday. For me it is a great lens on a tripod. It has a specific purpose for me. At my daughters wedding my P14-140 was a little slow indoors, compared to the wedding photographers BIG glass. I see the need for fast primes in certain circumstances and have bought the PL15mm. Gosh, that is fast. So what would a P42.5mm f1.7, do for me what the Ol60 does not do? Then I get a P25mm f1.7 to make it a trio.