Well, I broke my MSF so that gave me a good excuse to check this powder out.
Color me pleased. I've definitely got to layer it on to get the same coverage as MSF, but unlike MSF, it feels very light on my skin, even with a few layers. MSF always starts to give my face a coated feeling after a few hours, while this powder is apply and forget. It does an excellent job covering up the pores and on my skin, which is very dry, it gives a nice balanced finish - not powdery or dry looking, but accenting the planes of the face, without looking shimmery. It's too much to call it light reflective or dewey, but it gives a very subtle, healthy finish to my face when applied over bare skin. It's less matte than MSF, but it's not a satin finish by any stretch of the imagination. I think I'd attribute this in part to the emollients in the formula - it certainly keeps my skin feeling comfortable and balanced. Also, the ease of application with this powder is really something to note - it's very difficult to put too much on or get a powdery fake texture you'd have to blend out. Very foolproof in that department.
I think this is the powder I'd use for days when just clean bare skin isn't alive enough looking. MSF I'd use if I wanted a little more formal but basic and natural look. After that, we're talking MCLP for something jazzier and after that it's time to break out the foundation (you all know me - foundation is not a regular thing with me, but I use the MSF SPF15 when I go for it)
NC15 and I bought Light - it's very youth-ifying. I'm using a 138 for it and it comes packaged with a sponge puff for on the go application if you need it. If you already have MSF, I wouldn't say you need to run out and get this instead unless you really want something lighter and easier to apply than MSF or if you have extremely sensitive skin that doesn't like to feel coated or disturbed.