The screen is meh, too
The LaVie Z's display looks better on paper than to the naked eye. Its resolution of 2560x1440 amounts to 3.7 million pixels--right between the 2 million pixels in the 1920x1080 panel in the HP Spectre x360 and the 5.7 million in the Dell XPS 13 2015. When I measured the brightness, however, it maxed out at 235 nits--which just isn't bright. The XPS 13 2015, for example, hits 400 nits. This could be another conscious decision by Lenovo/NEC to control power consumption, but it's disappointing regardless.
The display quality varied. I didn't see excessive bleeding from the backlighting, and compression banding was kept to a minimum. Backlighting evenness was mediocre, but that's with a white background on maximum brightness and in a darkened room--you'd be hard pressed to see it under "normal" conditions. I still judge the panels in the Dell XPS13 2015 and HP Spectre X360 to be better here.
Viewing high-resolution images, I'd say the panel in the LaVie Z I have is under-saturated compared to the competitors. That may be a result of the anti-glare coating but I also found the off-axis viewing to be inferior to the competition.
Performance is great
The good news? Performance is pretty awesome for something this light. I'll start this off with our grueling Handbrake test that takes a 30GB, 1080p MKV file and transcodes it using Handbrake. Not only does this show how well the CPUs in the laptops perform, but it also shows you what happens to performance under a heavy, long workload. You'll see the same result from something that pushes the GPU for long periods of time.
The Core i7-5500U in the LaVie Z turned in top performance and didn't appear to suffer thermal throttling during our two-hour plus job. The chip is rated only slightly faster than the CPU in the next-best Dell XPS 13 2015, and this performance is pretty much in line that.
You may not think thermal throttling is an issue, and in some ways it isn't, because, you will feel it. You're ostensibly upsold on "faster" laptops based on the pricier Intel chips inside. If your Core i5 is throttling you all the way down to Core i3 performance, what did your money get you? For example: The CPU in the Surface 3 Pro is the same as the ThinkPad X1 Carbon 2014 yet, its performance dive due to thermal throttling, as seen in the 3Mark skydiver results (above), iis significant. Despite being incredibly light, however, the LaVie Z doesn't give up much in performance.
Fair battery life
The most important performance chart for many will be battery life. I used BAPCo's Mobile Mark 14 to measure how long the laptop will run under typical office drone tasks. By that I mean Office, Acrobat and other All Work and No Play tasks. Mobile Mark 2014 tends to give you a best-case scenario in battery life for Office Drone work. It even lets off the laptop screen for a few minutes to represent a break you might take during use.
Sign up for CIO Asia eNewsletters.