I've used a PC based slow mo editor with 30fps. The results are fair to average. These programs prefer 50fps and above for the best results.
Some conclusions are that slow mo is still best done with camera hardware like a Gopro with 60fps ++

Have any videographers experimented with the 60 fps 1080p versus the 120fps in 720p for youtube/pc based videos?

Does the 120fps give smooth slow motion?

Any other quick tips for using the Gopro for R/C videos that you could share would be appreciated.

Anyone got news on the Gopro4 with 240fps at 720p??

Thank you.