And inside the case of the Surface Pro, everything is different from the Surface RT, starting with the Intel Core i5-3317U CPU and integrated Intel HD Graphics 4000, which make it a real, powerful PC. Then it adds 4GB of RAM and 64GB or 128GB of storage.
Windows 8 takes up space on the SSD, cutting the available storage down to just 29GB and 89GB, respectively. You can get more space by archiving the recovery partition onto a USB stick and adding a 64GB microSD card (the largest on the market today).
But to put things in proportion, with Windows 8, the default Windows Store apps and Office 365 Home and Business downloaded and installed, and before archiving the recovery partition, we had 28.6GB of space free on our Surface Pro's SSD.
There are only a handful of ports and sockets on the Surface Pro, but again they're different fro Surface RT; on the left is a full-size USB 3 port, the volume switch and the headphone jack.
On the right are the microSD card slot (more convenient than hiding it under the kickstand), the magnetic power port (which we'll come back to later) and the mini DisplayPort connector. That's there because Microsoft expects business users to want to connect to monitors and projectors, but you can get cables that connect to your HDMI TV as well.
The other big difference is the screen. Turn it off and it's so black that it's almost impossible to tell where the bezel ends and the screen starts; it's even blacker than the Surface RT screen.
That's important, because the screen is never going to be blacker than when it's off - and most LCDs are more of a dark grey than a true black when they're off. Because there is no air gap between the layers of the screen - even with both touch and pen layers in there - the Surface Pro screen has true blacks. And very little glare.
Turn it on and you get rich, vivid, accurate and not over-saturated colours, and crisp, bright white. Other screens look slightly grey, yellow or pink next to the Surface Pro's gorgeous screen. The 1920 x 1080 resolution is higher than the Surface RT and shines when you're watching videos or looking at photos.
It also makes Windows applications and web pages look utterly tiny, so the default settings crank the DPI up to 150% (oddly, setting the Surface Pro to UK settings knocked that down to 125%).
This makes documents and web pages readable but makes window titles and scrollbars look a little oversized by comparison, so you may want to experiment with tweaking this to a custom DPI setting. Normally we'd say "that's a Windows problem" but given that Microsoft developed Windows 8 and Surface Pro side by side, it would be nice to have seen this look less strange on the showcase Windows 8 device.
It's the only drawback on one of the most beautiful screens we've seen on a PC this year, though.
The top of the case has nothing but the power button. The design here is slightly different from the Surface RT and may account for the fact that Surface Pro doesn't have the same phenomenal Wi-Fi detection. It found only 10 of the 13 wireless access points the Surface RT found in exactly the same position in the office.
There's no 3G or LTE option, but you can use your phone, a mini hotspot such as a MiFi or plug in a USB broadband dongle to get online if you need to. After all (we're going to keep saying this), it's a PC.
Even though this is an Intel Core i5 PC with vents and fans, it's not hot or noisy thanks to the efficient cooling. After running all day the case is barely warm to the touch and we could seldom hear the fan over other office noise, even with demanding games running.
The line of vents runs around the edge of the top half of the tablet, lining up beautifully with the kickstand (the vents stop where the kickstand starts). The line of the vent also makes it easier to feel where the kickstand is so you can open it without looking (there's still a small groove on the left to use if you have no fingernails, and the kickstand still opens and snaps shut with a satisfying expensive-car-door sound).
As on the Surface RT, the Surface Pro's kickstand puts the screen at a great angle for watching movies when you put it down on a table, or for typing or doing a video chat - the angle puts the camera at eye level with your face in view so you don't have to keep looking up.
What about for using Surface Pro as a laptop? Because the Surface Pro is thicker than the original Surface RT, the sides are bevelled at a different angle and the kickstand sits at a slightly different angle as well. It also has two tiny projecting feet at the bottom of the kickstand (each 2 inches wide) and we found the combination made the Surface Pro a little more stable when perched on a knee or lap.
How stable it is depends on how you sit and how long your legs are; if you can get your legs flat and they're long enough for the kickstand to perch on your knee, the Surface Pro is perfectly stable and you can type and tap the screen firmly without it over-balancing. If you prop your feet up, or you're tall, there's no problem.
If you're short and the keyboard and kickstand don't fit on your lap or the chair is the wrong height so your knees aren't at the correct ergonomic angle that keeps them level, you have to sit at an odd angle or risk the Surface Pro tipping backwards or forwards from time to time.
The extra weight of the Surface Pro may also help here; it's very well balanced and doesn't tip as easily as the Surface RT (in particular it's less prone to tipping forward when you move your legs).
A normal notebook wouldn't have that problem - but then you wouldn't be able to rip the keyboard off a normal notebook to turn it into a tablet.
The thicker, sturdier keyboard on a convertible such as the Samsung Ativ Smart PC Pro or the Lenovo ThinkPad Helix means these balance on your knee like a laptop - but they're also thicker and heavier than a Type or Touch Cover.