I've got the Hobie Full Auto harnesses and I think they're great. I think the Convertible can function similar to a Full Auto, but the Convertible can also strip down to just a bucket-type. I was recommended to go to the Full Auto rather than the Convertible - it wasn't much more expensive and the person said these had better support.
I started a post about 18 months ago - check it out here:
http://www.hobiecat.com/community/viewt ... light=auto . There was lots of great help given to me in that post.
Good luck