The Spark is significantly inferior to the Mavic, and since the arms don't fold up, isn't even any smaller than the Mavic. I have a Mavic Pro and there's zero chance I'd trade it for a Spark even if price was more of a concern.
Also: no 4K video (makes a significant difference in sharpness even when downsampled), 2-axis gimbal (that's the real killer) and significantly shorter flying time (16min vs. 26min, but that's really more like 10min considering you have to bring it home with enough lead time).
Also: no 4K video (makes a significant difference in sharpness even when downsampled), 2-axis gimbal (that's the real killer) and significantly shorter flying time (16min vs. 26min, but that's really more like 10min considering you have to bring it home with enough lead time).