This brick pictured above is actually a bit of a drone sandwich. It's the GDU 02, a compact camera drone with a 4K camera, retractable legs and a controller that sandwiches underneath it so you can transport both while protecting the camera gimbal and the thumbsticks. With vision positioning, obstacle avoidance and smart shooting modes, it's a low-cost competitor for the DJI Mavic.
For something that is around US$65 cheaper than the Mavic Air, the GDU 02 packs plenty of goodies. Comparable in size to a Mavic Pro, it features forward-facing obstacle avoidance to help you not crash it, and can transmit high-def video back to a smartphone about one-kilometer (0.6 mi) away. Like the Mavic drones, it fits easily in a backpack with your camera gear, and unfolds and flies within minutes. The only fiddly bit is sticking your smartphone, in my case a Pixel XL, in the stretchy controller clamp – and that's a 10 second job.
The controller won't let you fit larger 8- or 10-inch tablets in it – the Mavic drones don't either – but then portability is the name of the game here.
GDU 02: folding props help keep this thing very compact for travel, and fling out by...

Flying the GDU 02

Takeoff is a one-button affair and landing is nice and easy compared with a Phantom-class drone. Regular mode gives you smooth, slow movement to help you capture the smoothest motion you can, and Sport mode peps things up and makes it much more responsive. That makes it more fun to fly, but your footage gets pretty jerky if you're not super smooth on the sticks.
Like the Mavic, the 02 struggles to compensate for high winds due to its low weight. But the GPS/GLONASS and vision positioning systems help it hover reasonably steady within a radius of a few feet. I'd consider this a fairly friendly and easy drone to fly, with a minimal learning curve.
You can pilot it manually, or use a bunch of smart shooting modes. There's Circle (points of interest) mode, which frankly is a bit wonky. It seems moving sideways and rotating smoothly to keep a subject in frame is as tough for a computer as it is for a human operator. There's Selfie mode, in which the camera nicks off backwards to reveal your magnificent surroundings, and it works well.
GDU 02 controller with Pixel XL
Gesture recognition mode lets you hold up two fingers to trigger a three-second delay on a still shot, or hold your whole hand up to start and stop video. It's a little hit and miss but mostly fine. Rocket mode is handy if you don't trust yourself to literally hold the throttle upward. And there's a point and drag, visual tracking Follow-me mode that seems to do a great job – at least at slow speeds – of keeping you in frame and following you as you run around the place.
The 02's dual-camera obstacle avoidance definitely helps give you peace of mind in autonomous flight, such as return to home mode, and when you're on the sticks it does a good job warning you when you're getting close to something, and stopping you when you do get too close.
Battery life is rated at 20 minutes of flight time, and that may be true. But the drone won't take off with 20 percent battery or less, and if it's in the air when it hits the 20-percent mark, it'll start trying to return home and land. So, realistically, you get about 16 minutes of usable time. That's well down on the Mavic's 30-minute rated flight time, and a key area for improvement as GDU continues to develop this series.

Video and photography

Video quality out of this tiny 4K camera is pretty good. It doesn't handle transitions in exposure very smoothly, and like many drones it struggles to stabilize yaw movements, so turning the drone while you shoot often ends up giving you footage that's difficult to watch. Perhaps the footage feels a little too sharp in full 4K resolution. And there is a certain uneasy jitter to it sometimes, for which I'm not sure whether to blame the gimbal, the camera or the video compression. But that's looking with a critical eye; for the most part it's a good camera. Detail is great and colors look nice when you get the right light.
Here's a quick bit of sample video. Full-screen it and select the maximum quality to see it at full resolution, but be aware there's some YouTube compression going on and the original footage looks a little better: