Features & Specs
Gesture Control
The Spark's Gesture Control made heads turn when it was unveiled last year and it was probably the first consumer drone to feature it. For example, you can gesture the drone to move left or right. You can even gesture for it to take a photo or video. Gesture Control is a great feature to use when you find it inconvenient to get your smartphone or remote controller out for a quick photo or video.
In fact, the Spark can be flown exclusively using Gesture Control although this is something that I don't recommend since it can sometimes fail to recognize gestures. Without a smartphone or remote controller, it is possible for the Spark to stray a few meters above ground in certain situations and when that happens, trying to get it to land is going to be very tricky. In one such situation, I have found that turning the remote controller on solved the problem. With the RC connected to the Spark, you'll be able to land it safely.
Intelligent Flight Modes
One thing that sets the Spark apart from its rivals is its intelligent flight modes and the Spark has plenty of these. These modes are only available via the DJI GO 4 app and cannot be accessed from the RC remote controller. With intelligent flight modes, it is possible to take professional aerial videos at the press of a button.
For example, the Spark's Quickshot modes allow you to perform flight maneuvers such as Circle and Dronie automatically. If done manually, such flight maneuvers would require expert piloting skills and experience. I have tested all these modes and found them to be fairly reliable. They certainly are a lot more accurate than my own manual piloting skills when it comes to performing complex aerial maneuvers.
One feature conspicuously missing on the Spark is waypoint navigation which is available on other DJI drones such as the Phantom 4. Although this feature is not available on the DJI GO 4 app for the Spark, you can always install 3rd party apps such as Autopilot that have it although this could void your drone's warranty should you crash it while using a non-DJI app.
GPS and VPS
Two key features of the Spark that make it very easy to fly are GPS and VPS (Vision Positioning System). Without GPS, features such as QuickShot and FlightAutonomy will not work. I have done a few dozen flights with GPS and have not encountered any issues so far.
Thanks to VPS, flying the Spark indoors is so easy. The two downward-facing infrared sensors and single optical sensor allow the Spark to accurately hold its position and altitude. These sensors work up to a height of 8 meters and they've always worked well whenever the surface below is optimal for sensor tracking (reflective or transparent surfaces tend to confuse the sensors and can cause VPS to fail). So far, I've not faced any serious issues with the Spark's VPS.
The combination of GPS and VPS makes the Spark very easy to fly both indoors and outdoors as long as you're flying in optimal conditions.