Holy cow the new em-1 is a smooth runner. When I saw it I almost drooled all over it. I tested it on 18" radius ,guess what, no derails! But it does not look right on 18" so I do think 22" is the best radius to run it on. Over all ,I completely give it ,on a scale from 1 to 10 ,I give it an 11 1/2 stars.