I'm fairly lucky to have a car that was turbocharged from the factory. Many of us EVO guys are able to get away with just an APexi AFC to run most of our fuel injection tuning. However, seems more and more people are starting to run the AEM EMS. Sounds like a good system, but its pretty expensive.

What are your thoughts? Right now my car is pretty stock, but at what point do most people go with a system like the EMS?

I would just keep your stock ECU and get it flashed. Much easier, and much less expensive, and less room for error.