I just bought an AR150G for use largely as a graphic design machine; I chose it primarily because the screen is one of the best I've seen on any PC laptop, in terms of color consistency across the screen. While I'm still going to hook it up to an external monitor most of the time, I wanted something I could take to client meetings to show work, and this machine seems like it will fit the bill nicely. It's heavy and the battery life is atrocious, but it's probably the best-looking PC laptop I've ever seen (gotta impress the clients, you know), and it should work for what I need it to do (work and games).
One issue to consider for design is what sort of design you'll be using it for. I chose to forego the higher-res screen simply because most of my work is for the Web, and I need to see it at something approaching "real world" resolution. If you're doing print design, I'm sure the higher the resolution, the better. I personally would have preferred the glossy "premium casing," as the matte version attracts fingerprints also, but is somewhat harder to clean. And the video card upgrade is most likely worth it if you play games.
For $200, that's an excellent deal. However, for what it's worth, I got my AR150G (similar to the AR170, but non-configurable) for $1,698.99 after rebate from Amazon.com, so you could save some money over Sony's site if you can live with the default configuration.