Sony is absolutely crushing it in the Mirrorless market. I remember the weird looks I got when I was excited to pick up the original NEX-5 the day it came out. Sony hit the ground running and hasn't stopped since, as evident by todays lineup of cameras offered by them.
I would say comment why, but I think I know most of the reasons... Its just weighing up which is worth the money... I think the G4 hits the sweet spot for size and I know the cameras are much better... But the 6 is a NEXUS! Not to mention better battery life (although not removable) and a metal design... Is there anything else I'm forgetting?