This is my 3rd Fitness Fleece. There's nothing quite like them: warm enough to use as a sweater, thin enough to wear under a jacket, and soft enough to wear as a shirt. A very versatile piece of clothing.
I bought this fleece in preparation for a trip to Germany in November. I layered it under a waterproof jacket to avoid taking a bulky winter coat. It was perfect! It was thin enough to layer and not bulk up, but still kept me really warm in cold, wet weather. It's also cozy enough to wear like a sweater/sweatshirt inside. I do usually wear a M, but bought this in a small to avoid bulkiness - it turned out that a S was a perfect fit anyway.
I expected this fleece to be lightweight, but it is very thin. Even though it has been washed several times, it continues to leave lint on my clothing. I wouldn't buy it again.
Very, very comfortable, amazingly warm and light, no statics either, doesn't even attract dog/cat hair! Snuggle and flexible in gym or as a perfect liner for skiing. Just ordered a second one!