Usability is the first area where the XPS 15z hits a minor road-bump. Its chiclet keyboard is one of the few parts of the laptop that's not metal, though the keys have been painted an attractive silver shade to match the anodised aluminium shell. We're glad Dell hasn't included extra buttons other than the white-backlit power button, and this you'll find all the shortcuts on the top layer of keys, including one for ejecting a disc from the optical drive.
However, despite a good layout, keys feel just a little too small, especially the ones on the far right. This makes it easy to hit the wrong one when, for example, typing an apostrophe. More pressingly, though each key offers a positive click, they're just a tad too shallow for ideal comfort. Once you're used to it, working up a fast typing speed shouldn't be too much of a challenge, but it's just that slim models like the Lenovo X1 have shown us how good laptop keyboards can be.
Thankfully we have no complaints of the touchpad. It's large, smooth and sensitive, clearly defined and doesn't interfere with typing. Admittedly it's not quite on a level with the frosted glass offering on the Samsung Series 9, but it's comfortable and works well. The pad's individual buttons are likewise a pleasure to use, offering a crisp, easy click.
Moving onto the 15.4in screen, the XPS 15z is available in three different configurations, the cheapest of which offers a 1,366 x 768 panel, while the other two bump the resolution up to a whopping 1,920 x 1,080 (also known as Full HD). This is the highest resolution that can generally be found on laptops this size, and it's great to work with, but it does add £100 to the price.
Our sample came with the Full HD display so we can't comment on the quality of the lesser option, but we can tell you the one we have is nearly as impressive as the chassis it's nestled in. While viewing angles don't match up to the IPS screen on the Lenovo ThinkPad X220 or the unusually superb TN in the Samsung Series 9, they're the next best thing. Horizontally they're almost flawless, while vertically they only become unwatchable from below.
Contrast is decent though not perfect, with the screen unable to distinguish the two darkest or lightest shades of the greyscale. However, this is compensated for by deep blacks, even backlighting and not a hint of light bleed. Furthermore there is little sign of unwanted artefacts such as dithering or banding. Sharpness is also excellent, helped by the fine dot pitch that cramming a 1,920 x 1,080 resolution into a panel this size gives you.
On the audio front, meanwhile, we're a little disappointed. The XPS 15z's speakers face upwards through the generous grills to either side of the keyboard and give reasonably roomy sound at a decent level of volume, but mild distortion and an overly harsh delivery that's lacking in bass mean you're better served using external solutions.