When closed, the IdeaPad Flex 15 looks like a Yoga 13 with its black soft-touch plastic lid and chassis; the sides are a dark grey. The only thing that sets it apart from its older 13" brother is the black aluminium palm rest when the display is open. But whereas the Yoga 13 can flip into four modes, the Flex 15 only switches between Laptop and Stand modes. The transformation, however, is just as simple and reliable as on the Yoga 13. The hinge breathes solidity and appears to be the same type of hinge as the Yoga. The Flex 15 fulfils two needs: productivity in Laptop mode and photo viewing and film watching in Stand mode. The touchscreen is responsive and precise, making for a comfortable user experience.
The chiclet keys are well sized and offer nice resistance and a supple rebound, making it a pleasure to work with. The spacious touchpad is precise and recognises all of the Windows 8 touch gestures. In Stand mode, the touchscreen is closer to you, making it a good way to put Windows 8's touch-happy ethos into practice.
The ports are satisfactory: one USB 3.0, two USB 2.0, Ethernet, HDMI and a headphone/microphone combo jack. There's no DVD drive, which is a shame given this model's multimedia focus. The wireless connectivity consists of Bluetooth 4.0 and Wi-Fi b/g/n. We measured the Wi-Fi signal at -47 dBm from 5 to 10 metres away and -52 dBm from 20 metres away.
The heat dissipation could be better, as we picked up temperatures of up to 38.2°C on the left side of the keyboard and up to 49.7°C around the air vent on the underside of the chassis. Part of the cause of these warm climes is the fan, which doesn't expel hot air fast enough; the upside to this is that it stays quiet at a maximum of 38 dB(A).
The glossy 15.6" touchscreen has 1366 x 768 pixels, and is simply a terrible display, starting with the low contrast (424:1) and maximum brightness of 209 cd/m².
Grey colour temperature
And then it just goes from bad to worse. The colours are all over the place with a Delta E of 12.9 (the requisite three or below in order to have faithful colours is quite far off) and an astronomic colour temperature of 20,263 K (light years away from the ideal 6,500 K). In other words, if you plan on buying clothes online, don't do it using an IdeaPad Flex 15, because the colours won't look anything like they did on the computer screen when you bought them.
The sound quality is standard for a mid-range laptop. The speakers located on the bottom won't wow any aficionados; there's a good deal of power, but not enough bass or highs, and some major distortion. They're fine for listening to talk radio, skyping or those little "dings" for the Windows error messages, but that's it.
The in/out combo jack is satisfactory with an adequate stereo image. The power, distortion and dynamics are all average.
Note: The model we were sent to review features an Intel Core i5-4200U processor, 4 GB of RAM, an Nvidia GeForce GT 750M graphics card and a 500 GB hard drive. The comments above refer to all versions of the Lenovo IdeaPad Flex 15, whereas the sections below apply only to the model we tested (see inset below). Available configurations may also vary depending on the country/region in which you live.
Our model's configuration (Core i5-4200U and a mechanical HDD) obtained a score of 77 in our in-house rating system, which places it smack-dab in the middle in terms of performance for a convertible laptop.
If you look at the performance achieved on laptops that contain a solid-state drive (such as the Samsung Ativ Book 9 Plus), you can see a clear difference between systems that don't have an SSD, due to the slower access speeds. A good compromise for the Flex 15 would have been to use an SSHD instead of the HDD.
Our model of the IdeaPad Flex 15 is good at performing simple tasks such as word processing, web browsing and small-scale photo editing, but for bigger tasks such as video encoding, you'll have to get used to waiting.
Lenovo the gave our model an Nvidia GeForce GT 720M video card, which did not perform well in our standard tests.
It's more or less equivalent in performance to an Intel HD Graphics 4400: it will run Windows Store games fine, at which point Stand mode comes in handy, but for bigger games, only older or independent titles will run with adequate gameplay. HD videos, however, decode perfectly.
MOBILITY / BATTERY LIFE
We got the IdeaPad Flex 15 to last 6 hours in our battery test (continuous video playback in airplane mode with the brightness at 100 cd/m² and headphones plugged in), which is quite good for a 15.6" laptop. Of course, at this size it isn't as easy to tote around as an 11" or 13" machine.