Of all the models in the set it's Radagast that has impressed me most, for a number of reasons, but primarily for the level of detail.
He comes, as with all GW's plastic heroes, on a single sprue. Made of five parts, with another two part making the base, the interesting thing is how the model has been split.
Rather than try and describe things, here's the building diagram (once again without the parts numbers from the sprue). Look at how the body makes the core of the model, and the coat builds up around it, rather than having it as a single piece. It's steps 2 and 3 that warrant interest, as the half of the coat added in step two is held on by the arm, rather than under its own power. This sort of layering will hopefully be seen in other models to come, as it opens up a lot of possibilities. Note that the branch on the base is a pig to get on no matter what order you do things. And talking of problems, I snapped his staff getting it off the sprue. Cue much swearing looking around the the small bit that had pinged off, and great relief when I found it.
The detail on the coat is fantastic, and really adds to the model. Here's the raw plastic vs GW's painted version.
That's going to be a trial to paint. The beard on the other hand is going to look good, even with just a drybrush, thanks to the detail.
I like Radagast as a model, and he's a nice addition to the boxed game. He comes with his own rules sheet, which includes a new scenario involving him and Gandalf fighting off Goblins.