I posted my 2 ct on that issue some time ago. No matter what I shoot, what lens I use, whatever I do in PP ... , monitor, magnification, print size, ... - right next to images from my NEX-7 (even with the less than stellar 1855 kit lens or the same lens via adapters) the Fuji images look pretty flat, like images, 2 dimensional, sometimes even with a painterly character - whereas the images from the NEX pop like you're actually looking at the scene you've captured; the RAWs have far more microcontrast to start with. If it weren't for the obvious advantages of Fuji X and the lack of alternatives for my needs I would have sold that stuff already long ago.
Enjoy your Sigmas, Pete, I'll be shooting some film in the meantime, got some fresh stuff coming in these days.