Ive used both the old K30 and the new twin K30. The old K30 sucks - clumpy, static and just a terrible grinder all around. The new Twin k30 performs much better - with less static and clumping, in the limited time Ive used them for competition.
The Kony-E would be my choice of grinder if money wasnt an issue. For low/med cafe usage, the Kony-E would made the perfect dedicated espresso grinder. Many cafes in fact put up 2, 3, 4 Roburs for espresso when the volume being output through them only justifies a Super Jolly or Major at best.