just got an SJCam 4000+ this week after much deliberation and a few threads on her asking for advise
It seems great, is genuine and has updated to latest firmware no problems (update to something like v2.1 first then to v2.6 rather than going straight from the 1.6 mine came with to v2.6 as it doesn’t like that very much), image quality seems nice, shifting the settings around a bit has improved it no end
Has all features of the GoPro including wifi and screen, 2k recording, rotation, image stabilisation etc plus it can be used as a dashcam (has instant on and record when connected to a power source and cyclic recording) which a GoPro cant which was the decider for me as it gives it another use and I drive quite a bit for work
I paid a bit more to ensure UK stock and reduce risk of getting a fake off one but was still only £81 at Amazon here – http://www.amazon.co.uk/gp/product/B01236R1X2?psc=1&redirect=true&ref_=oh_aui_detailpage_o05_s00
Forfilled by Amazon so easy returns if not satisfied
Avoid the SJ5000 series but if you want something like the newer smaller GoPro look at the M10 (or wifi version) still around £100
Cheap set of mounts including car and chest mounts which also seem fine (not used in anger yet though) here – http://www.amazon.co.uk/gp/product/B00V4584GW?psc=1&redirect=true&ref_=oh_aui_detailpage_o04_s00