At today’s Build 2012 opening keynote, Steve Ballmer used several devices to show off Windows 8, but there was one that stood out. The Acer Aspire S7, said Ballmer, was the one device that was turning all the heads within Microsoft – but even from the second row of the auditorium it was tough to make out what was so special about this little laptop.

It took no more than three seconds with the device in the demo hall to work it out.

The Aspire S7 is the most gorgeous Ultrabook yet. It’s a 13.3in device decked out in silver, with a magnificent Full HD display. The tone is vibrant and the Metro desktop looks wonderful in all its many colours, and it’s a touchscreen, too, to take full advantage of Windows 8’s two personalities.

There’s a USB 3 port on either side of the base, along with a microSD slot and a headphone socket. A micro-HDMI port on the back is the only video output, but that’s to be expected given the thin chassis.

But the main thing that strikes you is just how much is crammed into such an incredibly small and light chassis. It’s less than half an inch thick and weighs 1.3kg, yet this tiny beast packs a Core i7 with Intel’s HD 4000 graphics, 4GB of RAM and a 256GB SSD. Whatever we tried on the S7, it responded instantly – including prodding the screen, which very quickly became second-nature with the screen so close to hand.

Better still, other than a single slightly warm strip near the rear of the base, the S7 didn’t heat up at all during our testing, with the vents on the back barely even registering heat when we held our hand over them. Of course, we couldn’t run anything particularly intensive to see if there are fans waiting to blare into life. We’ll have to wait till we get our hands on a review unit for that.

The info card next to the S7 gave a price of $1,399, and we’re a little disappointed to see that translate to £1,399 at Amazon. If that’s too much, there’s an i5 version with 128GB SSD for £1,149. Either way, it’s a lot of money to pay – but from our brief hands-on time this is right up there with the MacBook Air both for build and sheer desirability.