Flying only on the Vatsim for a couple of years, so don't know anything about Ivao.
Regarding controllers , especially the Approach controllers have to say that more and more I have bad experience.
On the final approach you can see that they are making mistake or they will make a mistake, and you have to follow their instruction, otherwise.....
I am flying with 747 and she is big and "lazy". She can not turn for 90 degrees in 200 meters, and that is what those controllers are doing. So after a long haul flight they mess up everything.
On the end I am looking for the airport without the controllers.