no, iVTEC isn't all that much different from regular VTEC. It still works the same. The kick ass part that only apears on the type r and type s is VTC which can advance and retard the intake cam in addition to changing lift and duration.
The real advantage of the K series (versus b-series) comes in the flow numbers on the head, and the fact that it is lighter and physically smaller than the B18 and has a larger bore (very difficult to do while maintaining physical size) which results in larger displacement.