It is noted that the superiority of the delta operator (DO) models over the shift operator (SO) ones, for small sampling periods, concerns only the recording of the model coefficients and some analytical calculations. It is also noted that in the simulations, making it possible to obtain the time response of the output for any input, as well as in the model identification under limited measurement accuracy, the superiority of the DO over SO models, for small sampling periods, disappears. These observations have an essential meaning since the mentioned problems of simulation and identification are important for applications.