It doesn't effect my car. I've done this on my 350Z with no issues. I think the people that had issues is because they didn't vent the proper hoses. They just sealed them all off. I'll try to get pics today. Mostly you want to put a small crank case breather filter (from K&N) on the hose that goes to the gas tank. Other than that the system works the exact same in the EVAP was installed. The EVAP is a simple air/ fume filter. All I have done is removed it and the system still operates the same.
DIY: EVAP Removal