The X18-m kit interests me the most. I'm actually considering it.
For the Vostro 1720, after you add the essentials (P8600, less power usage than Txxx line, and still better performance than the stock CPU), 1920x1200 res screen, dedicated video, 4GB memory, it still is around $900-1000.
For the DV4T, it's a solo core, and the dedicated video option is $150.
Give me back the DV8T for $999, that I can use. =D