Rating: 4 / 5
I have a 2008 MB Inner down Parka, and I wish I would have waited until the 2009 models were released before hitting "submit order."
I have a size small, which weighs in at 7.2 oz. The jacket is warm, and is my go-to insulation piece in 3-season weather. In my 3-season clothing set, I can layer it over a S/S and L/S base layer and a windshirt. I could also fit it under a windshirt if necessary. It also works well underneath my hardshell. Because of the close cut, I cannot layer a puffy vest underneath.
What kept this jacket from being a five are a few features (or lack thereof) that have been corrected in the 2009 model. My biggest complaint is that there is no hood draw cord. Because the hood is large, it can fly off in wind. Second, the cut is boxy at the bottom. I have mostly corrected this by going with a small size, but it could be nice if the jacket was more form-fitting. Also, the jacket could use more insulation so it could be used more effectively in a parka/half-bag situation.
Will Reitveld, in his review of the WM Flash jacket, compared the MB inner down parka with the WM jacket and the Nunata Skaha plus. All are lightweight hooded down jackets. While the MB was the lightest and cheapest of the lot, it was also the coldest because it used less down than the other two.
The 2009 jacket adds features that are not present on prior model years. First, they narrowed the cut for a closer fit. Second, they added more down, up to 2.5 oz, to bring it close to the WM model, which has 3 oz. Third, they added a draw cord to the hood and bottom hem - all of which create more thermal efficiency by sealing off drafts.