I'm with Arcane. Allies is one of the best decisions GW has made recently. It just opens up so many fun projects and builds.
I'm new to 40k. I had my Host of Worms army as an "art project" in 5th edition, but I never even played. Before that, I think I had a demo of 3rd and of 4th.
However, 6th has pulled me in to actually play. I think it started when I decided to finally listen to the first through Horus Heresy audio books. I had tried reading them before to no avail, but listening to them on my commute -- LOVED THEM. It finally cemented the setting in my mind and made me dive back in to my Nurgle based CSM army.
I love the hobby parts of the game the most. GW plastics are the best in the industry, without a doubt. So much so that I feel embarrassed for some companies who have recently started doing plastics.
The extra bits, the magnetization options, the ease of assembly and cleaning. All joys. I'm not the biggest on painting, but converting is my true passion.
I can't wait to get more involved in the local scene, even though I usually avoid LGSs, especially in campaigns.