The reason i went for the Innovate gauge is because the AEM product has a fixed calibration, which is fine if the sensor doesn't wear overtime and it's tolerance move but all sensors do. With the AEM product you have to then replace the sensor, with the Innovate (and most others) you just do another free air calibration and away you go.
I also like the fact that you can chose what AFR scale you want to use on the Innovate where as with the AEM gauge you stuck with Petrol AFR scale or Lambda.
Also the data logging on the AEM product is very basic, it's basically a MS notepad window with just readings on it, no RPM reference. Not an issue though if your data logging through your ECU though.