I'm not sure it's a similar model, but I have the
SZ2VP - a Core duo 2.16, the previous model to the SZ3VP. It's noisier than the Macbook Pro (and as a result it doesn't turn into a barbecue grill) but in terms of having something actually portable, the Sony blows the Mac away completely.
A shade under 1.7Kg for real, fully loaded with the same performance as the MBP.
Battery saving modes with dual display adapter (Macbook-like GMA950 for when saving power, Geforce when real graphics are needed).
The screen is really nice, better than the Apple laptops I've had in terms of quality, but the size may be a turn-off for some especially if this is your 'do everything' laptop. I generally find that the resolution and screen size is an acceptable tradeoff for having something relatively unintrusive. The build quality of the premium Sony laptops is something that Apple these days can't match.
One (always) Sony let down is the power brick. It's big. Why Sony, why?
But if you get around a lot and you want power on the move, Apple doesn't have anything to counter the SZ series. The carbon fibre lid is also raven-like as it changes shades with the light. Quite mysterious