Hmm, based on Fawkner beacon readings, generally accurate for the spots I frequent, my bottom end for grovelling/holding ground on my 2012 12m C4 on a 50fifty (fair bit of rocker) is 14/15knots average and on the 9m about 17/18knots. Fun kicks in at 3knots (of average windspeed) above those numbers and continues well above that.
I'm no pro, but a decent intermediate and I'd be skeptical of numbers much lower than these. That said, it's always a tough call to get precise numbers, but you can always compare with other kites/riders in the same breeze and on that test the 2012 C4s go very well in the right hands - given that it is a performance Ckite optimised for turning and unhooked performance, and not a race/flat kite.
If I wanted pure low-end/m2 I'd ride Edges, but my priorities are turning and unhooked performance for all-round fun, so I ride C4s.
As ever, a demo long enough to dial the kite in will quickly sort the reality from the hype. See your nearest Ozone stockist