Yes, air con makes no difference. Same behavior with and without air con. Sometimes it runs perfectly though and also when engine is cold there is no erratic idle.
Although, if it matters, steering wheel is not turning as easy as the ones on my other Alfas. I've checked hoses and replaced the spiral aluminium hose under the bumper which was bent a bit. Of course, changed the fluid as well but steering is still a bit harder. Wheel is still easy to turn but not as easy as others. Maybe difference between tire sizes is causing that, since i have 215/45/17 on this car and 205/55/16 on others.