I've been recently considering lighter options. (I have a K-30 and back pain
Also, my favorite lenses are heavy: Sigma 17-50mm, Rokinon 14mm, Rokinon 85mm.) Here are my conclusions:
Fuji X-E1 seems to be the best deal, IMO: lightweight (about 500 grams with kit lens), nice viewfinder, very good 16-50mm kit, decent AF, decent price (the new version, X-E2, costs twice X-E1's price)... Fuji has excellent, expensive glass. I wish DxO supported Fuji cameras though--they say it's not possible, due to a property of Fuji sensors.
The NEX series is great, except for the lens offering: no good normal zoom. The new Sony 16-70mm seems to have focus problems, which isn't acceptable given the price ($1200). (The newer Sony A6000 is currently the best mirrorless from Sony. It offers very good AF in addition to a 24mp sensor and a great viewfinder, but it's expensive.) If you don't need a zoom, you could just go with a NEX + the light&cheap trio from Sigma: 18mm, 30mm, 60mm.
Samsung: no viewfinder, rather noisy 20mp sensors, good optics.
M43 systems don't have much appeal to me. I looked at numerous pics, and photos taken with APS-C cameras still look better... It is my subjective impression that for pics taken in good light the IQ difference between FF and APS-C is significantly less than the IQ difference between APS-C and m43.
Now, after considering the effort of switching to mirrorless and other drawbacks that would come with such a switch (e.g., no in-body stabilization, plasticky construction), I decided to wait for the next entry-level camera from Pentax. Who knows? They might give us a 400+something grams camera...
(In my case, lightness trumps weather-sealing.)
Last edited by causey; 06-18-2014 at 01:09 PM.