In reply to The Lemming:
First time on here for years, since giving up climbing ive taking up m4/3 photography. The first questions that are bounced back are budget/body/proposed usage.
But in the meantime here are my thoughts:
Ive E-M1 & E-M10 bodies, Primes 9mmf8 bcl fisheye + 14mm f2.5 + 17mm f1.8 + 25mm f0.95 zonghi + 45mm f1.8 +75mm f1.8. Zooms 7-14mmf2.8pro + 9-18mm old4/3 with adapter + 12-40mmf2.8pro + 40-150 old 4/3 with adapter.
Olympus 5axis in body Image Stabilisation works very well indeed, for example you can easily hand hold 1 second waterfall shots. But attach those Pro zooms and im thinking m4/3 is no longer small and light.
Of all that gear ive listed the most impresive combo's are
1) E-M1 25mmf0.95, you can photograph a black cat in a coal shed with lovely bokeh. Manual Focus. Heres a family wedding shot of which i mainly used that lens indoors no flash https://flic.kr/p/SsNica
2) E-M10 14mmf2.5, ive just acquired this little panny lens from ebay and its a cracker. Small and light as m4/3 should be, SHARP AND CONTRASTY. https://flic.kr/p/23QiTXr
3) E-M1 9mm body cap fisheye manual focus. Always in the bag. https://flic.kr/s/aHskmvvo4Y
4) E-M1 75mm f1.8 league of its own https://flic.kr/s/aHskaow6us
If i were to recommend anything it would be the 14mm f2.5 as i love 28mm (equiv) and the 9mm fisheye. Whilst the pro zooms are good lenses they are the least used for me.
https://www.flickr.com/people/mgent/