I have a 1080 hd hero and the 60fps looks great in slow mo, but it takes a lot of space on your card, i've never used the 1080 res, the 960 looks great and takes less space.
Shot this riding the husky. I use the pal mode so it's 50fps then slowed down 50%. It's not uploaded in hd so the quality is so so.
http://www.youtube.com/watch?v=ZCwT8gP2vDM