Atc - vatsim should simulate this very well. I use rc4, which also does a good job.

Agreed, but I was referring to the out of the box product if somebody doesnt want to invest time to explore vatsim or buy add-on to compensate what FSX doesnt do well.. I found Vatsim not to usefull during training as most of my region is never (well, rarely) manned so you can try in other regions but that was not the main interest while training.

Interesting point of view. My PPL is far back but i remember having used fs9 During my training and i never felt it was negative. It help you practice the sequence of event.Radio communication is difficult to practice as well as ATC interraction with a software that doesnt expose you to the variety of situation in the RW. For me thats not something where FSX can help you much.

Well it depends, if you use VATSIM for instance, you can get that feeling, We for instance have made many ATC events in CENAMER (Central America) with real ATC controllers on the radar and me and some other real pilots have felt a very similar experience as in real life, actually the only difference I could notice is that spoting traffic in FSX or FS9 is more difficult than in real life (if you get rid of the lettering in FS)This is very helpful, and help me a lot when I was studying, learning to understand what is herad in the radio and all the phraseology