I forgot to add ... I don't yet do the hop and turn that you're talking about to get to toeside. I tried it once, caught my downwind edge, big wipeout, and haven't tried it since.
I either do a heelside to toeside carving turn for a transition,
OR the little "sliding/wishbone" turn from the Progression video .... where you turn the board sharply upwind to 90 degrees, then reverse to downwind but now facing toeside. (that sounds more confusing than it is....easier to see it in the video http://www.youtube.com/watch?v=rtg1u8eW0Fs
Hoping is much easier than sliding if you want to go to toeside maintaining full speed. The small amount of airtime gives you the chance to fully twist the 180 degrees. Don't have the kite too low to begin with. Have enough speed, don't be too scared, it is only water
Don't overtwist because you will catch an edge and faceplant. If you twist less than 180 you will be going downwind which is ok.