Glad I found this discussion; I just started back riding after not getting on one for about 8 years. I just ordered a 36 inch one yesterday. Can't wait to get that one.
Back in the late 80's I learned how to juggle on a uni. From the time I started til the time I got to where I was comfortable enough to do torches it took nine months to learn. Now I am struggling with it; but it should come back pretty quick.
One thing I have noticed is that riding a uni doesn't affect my BG nearly as bad as riding my bike.