The pen was responsive, though I generally find Samsung's S Pen smoother. I felt some slight drag when scrawling letters on the 4:3 screen, but given we were only using an early prototype, I hope this will get better by the time the ThinkPad launches.

The device isn't just for you to use in your hands, of course. Like a conventional laptop, the foldable ThinkPad can sit on a desk with its screen propped up to face you. Lenovo integrated a kickstand into the PC's back so you can prop it up to use it in All In One mode. In this configuration, connect a Bluetooth keyboard and mouse, and you can use the computer as a 13-inch desktop.

You can also fold the screen and set it up at a right angle so the bottom half of the device rests on the table while the top half of the display faces you. This is Laptop Mode, and it devotes the lower third of the panel to an onscreen keyboard you can use to fire off emails and tweets. Using the machine this way felt familiar, and very similar to Lenovo's dual-screen Yoga Book laptops that replace keyboards with a touch-sensitive panel or e-ink display. It isn't an ideal setup to get a lot of work done, but if you need a proper keyboard you can always connect one over Bluetooth.

There will be other connectivity options available like USB C and A, but as Lenovo hasn't finalized the system, we don't know what the actual array of ports will be yet. The company did tell us that the foldable will pack an Intel chipset and that it'll be an always connected PC, meaning you'll have a cellular radio onboard. It's also targeting a day's worth of battery life, and will pack things like dual speakers and a Windows Hello-friendly pair of webcams.

There wasn't much else we could check out on the prototype -- we watched some videos and browsed a few websites and the display was as vivid as most laptops today are. Since the foldable is meant to be a ThinkPad X1 product, Lenovo said it will have to meet rigorous durability and quality standards, so it should be well-made by the time it launches. The company also hinted at some features that would make the device better for multitasking on the go, but did not want to share details that could tip off competitors.

Though the prototype is basic, it offered a tantalizing taste of what a foldable PC could be. The design and bendable display were eye-catching and I love the idea of a laptop the size of a paper notebook. Without giving it a thorough try out in the real world, though, it's hard to judge how well such a format might actually work. I'm not sold on the durability of the display and the utility of a laptop without an attached physical keyboard. Lenovo has until next year to make a foldable that's as capable and useful as it is unique. In the meantime, the company's competitors have plenty of time to catch up and offer their own takes on the foldable PC. Hopefully, that means we'll be checking out an intriguing slate of new laptops with bendable screens soon.