I'll second this. If you're looking for a cheap, light notebook with mid-range features, look elsewhere; however, if you want a fast, portable machine for development/design, I don't know of anything better. I've had one for about a year (typing on it now), and it's probably the best development laptop I've ever used (maybe even best development machine, period).
The only drawbacks I've seen are the price (it's quite expensive) and Sony isn't very good about keeping their drivers up-to-date, so anything custom/customized in the machine (like the graphics card) is kind of annoying to get new drivers for.
The point about the drivers is a big one. I've had a few Sony laptops and I'll never buy one again because support is non-existent after a couple of years.
The only drawbacks I've seen are the price (it's quite expensive) and Sony isn't very good about keeping their drivers up-to-date, so anything custom/customized in the machine (like the graphics card) is kind of annoying to get new drivers for.