Ask HN: any experience with Sports technology?

Have you guys used video capture, motion sensors, or any other technology to improve your game? Did you find that it solved any problems? Helped you improve faster than you would have otherwise?

Here are some examples for Golf:

http://www.zepp.com/golf/ https://www.swingbyte.com/how_it_works http://www.swingsmart.com/

I'm looking into building something in this space and would like to get an idea of how well solutions solve current problems, what their shortcomings are, etc. Cheers.