I've got two U12s and one U14, and I race in a beer league. That can mean 7+ tunes per week. Another local race dad swears by the Discman. He says it's not only quicker but also easier to get a good result. And he thinks the result is more durable, ie they stay sharper longer.
I still consider myself a beginner at tuning, and mostly learned from these forums, some youtube videos, and personal sessions (one with fellow bear SMJ--thanks!). I do enjoy tuning, but have 2 concerns: 1. I have very little time and 2. I recently pulled my right neck and shoulder pretty badly and if I don't heal quickly tuning could be very painful.
Luckily I've got 2 other parents considering equal shares, which would be about $280 each.
Regarding the Discman Ceramic Edge Tuner:
1. Does it save that much time and pain? I presume I still need to finish the edge with a 600 stone, correct?
2. Is the learning curve very steep? Is it dangerous? Do I need a mask?
3. For someone with just a couple of years' tuning experience, will it be easier to get a better tune? (I know, impossible to judge.)
4. Is the result more durable? And if so, is a harder edge a bad thing?
5. Is a rotobrush a better bang for the buck to save time (and my right shoulder)?