Lenovo's London launch event last night saw the introduction of three new members of the world-number-one PC maker's Yoga line of 'multimode' computers: the 13-inch Android-based Yoga Tablet Pro 2 with a unique built-in projector; the Yoga Tablet 2, available in 8-inch and 10-inch sizes, running Android or Windows; and the 13-inch Yoga 3 Pro, an impressively thin and light convertible Windows ultrabook. We came away with a review sample of the latter, and here are our first impressions.

We hear 'thin and light' bandied around a great deal, but the new Yoga 3 Pro is the real deal. Measuring 33cm (13in.) wide by 22.8cm (9in.) deep by just 1.28cm (0.5in.) thick and weighing 1.19kg (2.62lbs), the Yoga 3 Pro compares favourably to Apple's 13-inch MacBook Air, which comes in at 32.5cm (12.8in.) by 22.7cm (8.94in.) by 1.7cm (0.68in.) and 1.35kg. Both laptops are light, but you can feel the difference when you pick both up. Compared to the previous-generation Yoga Pro 2, the new model — which is available in three colours (Clementine Orange, Platinum Silver and Champagne Gold) — is 17 percent thinner and 14 percent lighter.

The key feature of the Yoga range is its flexible 'multimode' nature, which asks a lot of the hinge mechanism. Lenovo identifies four usage modes: Laptop (standard clamshell orientation); Stand (keyboard facing down, screen outwards), Tent (keyboard and screen sections in a 'A' shape) and Tablet (screen rotated 360 degrees, flat against keyboard section). The most eye-catching innovation in the Yoga 3 Pro is its new 'watchband' hinge, a complex construction comprising no fewer than 800 components, with six attachment points rather than the standard two. In our brief experience with the Yoga 3 Pro, we found that this mechanism works very well, supporting a particularly good tablet mode. Hopefully, it'll stand up equally well in the long-term.

To help with these usage modes, Lenovo has introduced a new software tool called Harmony. This provides statistics on how much you use each mode, identifies your favourite apps in each mode and suggests others you might like, and optimises settings for certain apps. For example, it can enable motion control via the webcam when you're delivering a presentation, or adjust screen settings when you're reading an e-book.

As a regular ultrabook, the Yoga 3 Pro has plenty going for it. The display is a bright and sharp 13.3-inch touchscreen with a resolution of 3,200 by 1,800 pixels, giving an impressive pixel density of 276ppi (the 12.85in. Chromebook Pixel, by contrast, delivers 239ppi). The Gorilla Glass-protected IPS screen offers excellent viewing angles but is glossy, which could cause reflection problems in brightly lit environments. Above the screen is a 720p webcam.

There's plenty of room for a decent-sized backlit keyboard, which sits in a dimpled, rubberised surround containing a responsive multitouch touchpad with built-in mouse buttons. The island-style keys are well spaced, but may lack the travel and tactile response that some typists require.

A key reason why Lenovo has been able to design such a thin ultrabook is Intel's new 14nm (Broadwell) dual-core Core M-70 processor, which runs at 1.1GHz-2.6GHz (in Turbo Mode) within a thermal envelope of just 4.5W. Incorporating integrated Intel HD Graphics 5300 and supported by 8GB of RAM and a 256GB SSD, the Core M-70 platform should provide a good combination of mainstream-level performance and low power consumption. There's no fan, which makes for silent operation, and we didn't notice the system getting too warm — even when running a demanding benchmark like Cinebench R15.

For connectivity, there's dual-band 802.11ac wi-fi and Bluetooth 4.01, but no Ethernet or mobile broadband option. Despite its slimline dimensions, there's a decent selection of ports, slots and buttons on the Yoga 3 Pro. The right-hand side has a USB 3.0 port, a 3.5mm microphone/headphone combo jack, a volume rocker, a screen-rotation-lock button, a Novo button (for access to the BIOS setup utility) and the power button. The left-hand side has a yellow USB 2.0 port that doubles as the power connection (it has a notch to accommodate the special USB charging cable), a second USB 3.0 port, a Micro-HDMI port and an SD card slot.

The compact and lightweight AC adapter has a USB connection, and so can be used to charge other devices when you're on the road. The Yoga 3 Pro's non-removable battery delivers a claimed 9 hours of uptime — something we've not yet had a chance to put to the test.

To get a quick overview of the system's performance, we extracted its Windows Experience Index or WEI (a more convoluted process under Windows 8.1 than in previous versions). The component scores (out of 9.9) are as follows:

CPU score  6.5
D3D score  4.6
Disk score  8.2
Graphics score  4.4
Memory score  7.3

As usual in a system with integrated graphics the 2D and 3D graphics scores are the weak links, while the SSD leads the rankings. In use, the Yoga 3 Pro seems perfectly responsive with mainstream workloads; it also has a particularly nippy boot-up time. We'll be doing more benchmarking in the coming days to provide more detail. We also haven't had time to properly evaluate the Waves MaxxAudio-enhanced audio subsystem.

As an example of the new breed of Broadwell-based ultrabooks, Lenovo's Yoga 3 Pro looks impressive so far. It's very thin and light, incorporates nice design tweaks like the watchband hinge, has a great screen and seems to deliver decent performance in a fanless chassis without getting too warm.

The Lenovo Yoga 3 Pro will be available at the end of October from £1,299 or €1,599.