I'm in a similar situation....although I'm almost 2x the miles and I'm also considering the Michelin Premier LTX.
The Hankooks have been just fine for me, although winter traction isn't the greatest.
One thing I don't want to lose is the steering feel. While it's no sports car, I don't want it to feel any less disconnected.
I've read that the Defenders are a little "softer" due to the extra initial tread depth vs. the Premier, but the Defenders also provide better snow traction.
I read good reviews of both the Pirellis and Michelins(both the Defender and Premier), so it's a tough choice.
I know Peter had the Pirellis on his, but not sure if his saw much snow with them. I'm sure he'll chime in.