Sigh. Of course the video is recorded in 60fps, what I tried to say is SJ4000 records the same frame twice. Basically it's just like recording in 30fps, but because it records the same frame twice (30 x 2 = 60), the video runs at 60fps. When people wants to record at 60fps or higher, usually because they want to record high-speed action video (just like when you suggested to Me-262 that he can use it in race track), but SJ4000's fake 60fps does not give Me-262 the advantage of a smooth video playback. And when he slow-mo the video at half speed, the video will appears a bit jerky like 15fps, not 30fps when true 60fps slows down.
Watch Techmoan's review on SJ4000 WIFI:
You can skip to time 24:40 in the video when he explains the fake 60fps mode in SJ4000.
As for the resolution issue, I was referring to SJ5000+, not SJ4000. Users have shown 1080P mode in SJ5000+ is clear and sharp. But when they record at 720P mode, the video becomes soft and fuzzy. And when they record at 480p mode, the video just look atrocious and unusable.