It depends on the plane. Larger aircrafts where the flight is mainly instrumental and the G force negligible could be very close to reality if the different functionalities would have been better implemented, maybe it will be done in the future by ASOBO itself or through some MODs. Small aircraft (CESSNA) have most of the functionalities implemented and assuming to fly in a calm weather are in my opinion quite close. Fighter jets or fast propellers are instead and again in my opinion totally unrealistic