Go with the ThinkPad. I was never impressed with a Vaio, they seem to have a lot of flex to them, even in the screen part. All of those ThinkPads listed have tough cases. (I know the T6x has a magnesium frame, not sure if the T500 switched to Carbon Fiber)

The T500 is ideal over the 60/61p. You get a last-gen Core 2 machine with DDR3 RAM.