You had question marks so I thought you had some question about that. Guess you were referring to whether anyone had a problem with leaving CIN unconnected.
Certainly a particular CMOS device may allow operation without all the inputs tied, at least for a while, but subtle changes in the circuit, such as from moisture or noise pickup, could lead to erratic (and hard to trace) problems at a latter date. There are reverse-biased input protection diodes to both Vss and Vdd on standard CMOS circuits but I wouldn't depend upon those to provide a definite logic level as the leakage goes in both directions.