Used one for a bit. Didn't own it as i was borrowing it for testing.
Fantastic machine. But yes, the cost was ridiculous. It was a couple years ago (might have been a different letter at the time). was a core2 duo 1.2ghz, 2gb DDR2 ram, and a 64gb hard drive.
the form factor was amazing and it served me well for the 6 months i used it. But the cost was at the time over $2,000 for the machine.
A few things about it that i didnt like. The power of the graphics. Intel 845's were terrible chips. the sandy bridge of today is amazing in comparison. The keyboard layout was great, but the keys made a little too small, And cheap. I don't think i'm particularly brutal on my keyboards, But within 5 months the lettering and the texture of the keys were completely different. they were smoothed out and the painted letters gone. I touch type, so i could still use it, but this is a "cheap" feeling issue you shouldn't get in a 2000+ laptop.
Right now, from what i can see, the Macbook Air is the only ultraportable that truly feels like it's done right. The others i'm sure technology wise will keep up, and may even offer a few added features. But overall package and price, the Air is really really tough to beat. And unless these other companies can come out with some added feature or seriously undercut apple, they'll be fighting a tough uphill battle
A bit unfair in your comparison there then. I mean, if the MBA did not feel better than a "couple of years" old VAIO Z what would that say about the MBA?
New Z looks quite sweet. i7 2.7 ghz (with tb, 3.6ghz), 8gb 1333 ddr3, 256gb ssd. 13.1" 1600x900 display (ips?). 16.65 mm thick, 1.18 kgs (MBA: 17, 1.35).
Graphics-wise, it comes with an integrated Intel GMA 3000, but way sweeter: With your VAIO Z you get an external gfx -- 1GB Radeon HD 6650M -- which docks with your computer over "thunderbolt" (or, intel light peak). The same dock also includes a BR/DVD, and a bunch of ports (hdmi, ethernet, usb 3.0, you name it). Dock weighs 0.7 kg (less than 2kg total that is, if you feel like taking the dock with you).
7h battery, with optional "sheet battery" that gives you twice that.
Wow.
Too bad the price will be as extreme as the device... i wouldnt expect to find it under 2000 when it comes out. Clearly though, this device blows the MBA away. At least on paper... :- )

lets put it this way. If someone offered me to switch their fully geared Vaio Z (above) with my (soon to be) fully geared MBA, i wouldnt think twice about switching :- )