I have been using my E-M5II w/ fotodiox grip quite happily with the 12-40 for quite some time. Works well as a hiking kit aside from the inevitable too short/too long problem. With an upcoming trip to NZ looming (in Feb), I rented the 12-100 to eval as closer to an all-in-one solution and am now pretty sure it's going to replace the 12-40. It really is a pretty amazing lens. The problem is that even with the fotodiox grip on the E-M5II, it doesn't handle nearly as well as the 12-40. I (stupidly, perhaps) went to the local camera shop and tried the E-M1II with the 12-100. What a fantastic combo. Granted, it was a short session but immediately felt great. I now find myself considering the E-M1 II pretty seriously, despite being generally happy with the E-M5II. While the in-camera focus stacking, better hi-res mode (which I suspect I'll use a lot) and possibly better weather sealing are nice upgrades, many of the other advantages are things that I managed to convince myself that I wasn't too interested in. Between selling existing gear (including an A7II which I never really connected with) and applying some existing budget I can swing it, but it would probably take away from lens budget. (might mean going with the Sigma 30 rather than the O25 Pro for example, and/or forgoing the P8-18) So my questions are: - has anyone used the 12-100 with the E-m5II and gotten used to the weight? Did you change your technique? Other grip options? - for folks that have upgraded from the E-M5II to the E-M1II, does anyone wish they'd done things differently?