Right now all I have is a laptop (couldn't bring my last rig with me when I moved to alaska) So I'd have to buy all the peripherals again (Monitor, speakers, mouse/keyboard, etc).
I probably would build my own rig, but shipping to alaska is the real killer. All those separate components in their own boxes can be a real money sink. Even ordering everything together, shipping would be about $200 to were I live.
I'm going to college in South Dakota next year, and I'd rather have something somewhat portable (or easy to ship) like the x51.
The model with the gtx 660 seems like it would be the best bet for me. All I would need is a monitor and the actual system itself.
From what I can calculate, building a PC with similar specs would actually be more expensive because of the shipping. (If I had all the peripherals and only needed the components, that'd be another matter)
So, before everyone just says "build your own" please think of all the circumstances.