Hi, I'm contemplating a bit if a fast zoom would be useful to me. Top candidates seem to be the 40-150/2.8 and the 50-200 SWD. I already own the 150/2.0 and the 300/2.8 so "none of them" could be a fully adequate answer. Afaik, both have excellent IQ, with the 40-150 possibly having the edge. Also, it's a constant aperture internal zoom while the 50-200 is a variable aperture external zoom. I guess the 40-150 is faster at 150 mm, but the other one is longer. At 200 mm, the 50-200 is stil 3.5. The 40-150 with MC-14 is an f/4 at 200 mm. 40-150 will give me decent autofocus on all bodies, the other will only have decent AF on the E-M1. 40-150 is supposed to have much better transmission characteristics, which would give a definite advantage in low light. 40-150 is smaller and lighter. 50-200 can probably be found used on ebay at low-ish prices. Not the 40-150, yet. Another alternative could be waiting a few months more and save up to the 90-250/2.8. Thoughts? I mostly use my long lenses for birds and wildlife, but I also occasionally shoot some windsurfing. Edit: Two more things on the 50-200: On the good side, I effectively will get C-AF+MF. On the bad side: Terrible bokeh.