Choose a Specialty radius if you are particular about your radius. If you don't know what radius your skate blades are then the Standard 1/2" ROH is your best bet.
I have been using this tool for a few months now. It takes a little while to get the hang of but I would like to think that I am pretty good with it now. I have 2 boys that play a lot who I am on the ice with plus I play myself. Needless to say I have been looking for something like this. It is a must have for any hockey trainer as I have repaired lost edges on the bench and the player has not even missed a shift. I have done at least 40 sharpens with mine and its still sharpening. My experience is that I still get my skates sharpened at Pro Hockey life or Play it again but rather than once every 1.5 to 2 weeks I now do them every 2 months. Fits in my jacket pocket on the bench - so convenient!
I have been using the 1/2" ROH for about a month now. It works great. Its really hard to get skates sharpened in Wellington New Zealand. We have to ship our blades to Auckland. Now I can do them anytime. The only problem is that my mates keep wanting to use it. I suspect Blade Barber will have quite a following from down here! Keep up the great work.
My son and I have been using this device for a few months now and I really like how it works and the sharpen that you get from it. It did take a few times to feel comfortable using it. My son keeps it in his hockey bag and has used it a couple of times now when he has lost an edge on his skates. He really likes it. Great tool for a quick fix.