Just posted new post in my blog about couple new features in latest development branch of Slic3r software
http://pavel.karoukin.us/node/19
I really like this feature too!
I’ve been using Cura exclusively for months now, but slic3r v1.2.6 has grabbed my interest. I like the 3D layer view and the ability to just slice and send the gcode directly to my octoprint server with a single button.
I still run into a lot of random crashes, hoping those get ironed out soon.