We received the top-end XPS 15z, which rocks on with a Core i7 processor, 8GB of RAM, a 2GB Nvidia GeForce GT 525M, and a 750GB, 7,200rpm hard drive. To be honest, we think that for the vast majority of users this configuration will be overkill, though if you have the £200 extra to spare, it's not bad value for upgrading from a Core i5 CPU, 4GB of RAM and a 500GB HDD – especially considering it also doubles the memory on the GeForce graphics card.
As you can see from the results graph, our sample spec of the XPS 15z will easily cope with almost any task. It's not quite as fast as a laptop sporting an SSD and, unfortunately, Dell doesn't offer one as an option (with the unibody chassis making it almost impossible to upgrade to one yourself), but otherwise its powerful CPU and GPU, generous RAM and speedy hard drive make for a potent combination.
As with all Nvidia GPUs, the GT 525M supports Optimus graphics switching. This means that the 15z will use Intel's power-frugal integrated HD 3000 graphics where possible, and when the workload kicks up a notch with demanding 3D gaming or GPU-accelerated applications, the GT 525M card will come into play. It offers a moderate amount of gaming potential, managing 44.3 frames per second (fps) in Stalker at 720p and Medium Detail, though this fell to a barely playable 24.8fps at the screen's native 1,920 x 1080 resolution. Still, undemanding titles at moderate settings are a definite possibility.
Battery life is decent, which is good news considering you can't replace it with a spare when it runs out. In our non-intensive Productivity test, with screen brightness at 40 percent, it managed just a few minutes short of six hours – though this will decrease when using the dedicated graphics and/or wireless radios.
So the remaining question is whether the XPS 15z is worth your hard-earned cash. We would definitely recommend going for the Full HD screen, which means coughing up for the £999 configuration. On the other hand, if you do want a little more power and future-proofing, the £1,199 is very reasonable for the extras you get.
This configuration also compares very favourably with its nearest rival, the Apple MacBook Pro: you get a faster CPU, double the RAM, a larger, faster hard drive, more powerful graphics with better 3D support, a far higher resolution screen, and more versatile connectivity, all for £350 less! Of course the Mac still has the benefits of its more cohesive, slimmer overall design, the comfort of its keyboard, and better speakers, but that's simply not enough to give it the edge.
With PC rivals the 15z doesn't fare quite as well, though the premium it demands is justified to an extent by its premium construction, and its Full HD screen is still an asset few rivals can match. On the other hand, the lack of a Blu-ray drive option really hurts it here.
The Dell XPS 15z is the MacBook Pro of the Windows world, with a streamlined aluminium and magnesium chassis, good 1,920 x 1,080 screen, backlit chiclet keyboard and plenty of power under the hood despite being less than an inch thick. Unfortunately it gets rather audible under load, its keyboard and speakers aren't the best, and the absence of a Blu-ray drive holds it back from being an all-round entertainment centre, but if you're happy with a DVD rewriter and are after a chic yet competent machine, this is definitely one to consider.