Lovewool wrote a review of Marmot Guides Hooded Down Jacket - Men's on February 10, 2014
Familiarity: I've used it once or twice and have initial impressions
Fit: True to size
I wear a medium in almost everything including Marmot clothing. This jacket is great, except that my arms felt like they were being compressed. It was far more than the typical loftiness I get from most down jackets. When I was bending my elbows, I literally could feel a sense of compression that I don't get with any other down jackets or belay coats. Unless you're built like a skinny stick (my arms are NOT big), avoid this one. My other complaint is that there is no volume adjuster on the hood. One velcro placement in the back would add a lot of functionality. However, the tiny arms are a critical flaw.
I have no idea how Down Defender performance since I didn't own the jacket long enough to put it through its paces, but it is an otherwise great value jacket with a durable feeling nylon shell and plenty of warmth.