London - There are more hybrid laptops on the market than ever before. Here we test four of the latest contenders.
By EMILY JUPP and JAMIE MERRILL
HP ENVY X2
Although good value, the HP Envy x2 is unlikely to inspire the feelings of covetousness it suggests. As a laptop, the keypad is comfortably spaced. The widescreen format works well for watching films on the tablet but I found the 11.6in width unwieldy. It's also heavy, as a lot of the device's guts are inside the tablet, not the keyboard.
It has an impressive 14-hour battery life (10 hours for the tablet). Using the touchscreen in laptop mode confused it and I had to re-dock the tablet to make it work. I also found the docked screen to be at a neck-straining angle. But there are nice touches, such as the Windows icon. It lights up and vibrates when you touch it, returning you to the home screen.
Operating system: Windows 8
Processor: Intel Atom z2760
Hard drive: 64GB
The Surface is Microsoft's answer to the iPad or Nexus 10 tablet, but less sleek and more robust. It's versatile: like a tablet but with a kickstand and clip-on keyboard, so it can be used like a laptop. It also lets you switch between Windows 8 and a Windows 7-style format depending on your preference.
The keyboard cover is really clever. It's like a normal durable cover, similar to the iPad's, but it also houses a super-thin keyboard. If you need it for traditional desktop work on the go, then a laptop would be more comfortable to use. If, however, you want a tablet but occasionally need to type documents, it could be for you.
Processor: 1.3GHz Nvidia Tegra 3 CPU
Memory: 2Gb RAM
Hard drive: 32GB
SONY VAIO DUO 11
The Vaio Duo 11 has a screen that elevates as you slide it from tablet mode to reveal a dinky keyboard but no trackpad. Instead it gets a rather annoying stylus (there is nowhere to store it) and is a little too heavy really to use as a tablet.
The firm must be going for the executive market, though, as it gets VGA and HDMI ports if you want to hook it up to a bigger screen in the boardroom. And even the entry-level gets an Intel Core i3 processor, a 128GB hard drive and 4Gb of memory. Upgrade these and opt for a Core i7 processor and you'll need to part with nearly £1,500, and that's MacBook Pro price territory.
Thankfully, though, and like most Sony products, it's stylish to look at, and all models boast a fantastic 1,920 x 1,080-pixel screen.
Processor: 1.8GHz Intel Core i5
Memory: 4Gb 1,600MHz SDRAM
Hard drive: 128GB
LENOVO IDEAPAD YOGA 13
At first glance this looks more like a ThinkPad than a nifty hybrid but Lenovo's latest hybrid transforms from laptop to tablet by flipping the screen all the way around so it sits underneath the keyboard. At first it feels unnatural but you quickly adjust to the quirky set-up of the new IdeaPad Yoga 13.
It's now on offer at £1,099.99, which is (to some extent) good value when you consider it has 128GB of memory, a 1.9GHz processor and 4Gb of RAM. In the real world it doesn't feel as quick as you'd hope, though, and it slowed at times with multiple apps and windows running.
Operating system: WIndows 8
Processor: Intel Core i7 3537U 2.0GHz
Hard drive: 256GB - The Independent