Well, if I were starting over I'd probably still end up with the same system (see my Sig below) but my needs aren't your needs and over the years I've become more resistant to venturing out in wet weather with a camera so although my E-M1 and its kit lens are weather resistant that isn't a big deal for me. Fast single shot AF is important, though, and the E-M1 achieves that handily. I'm not into movies.
If m4/3rds was off the table I'd be very tempted indeed by the Fujifilm X-T1 (review
) and the first of the Fujinon weather sealed XF zoom lenses, namely the XF18-135mmF3.5-5.6 R LM OIS WR (link
), is just about to hit the shelves but it's not cheap! Fuji has also promised two more weather resistant zooms, the XF16-55mmF2.8 R OIS WR and XF50-140mmF2.8 R OIS WR, for the future.