I have owned both the DS 708 and the Maxisys.  I feel the scan tool is a great product but my gripe is with the MAF readings. I have asked this question before and so have many other people. I am frustrated that no resolution has been made. It seems to me it would be an easy fix. I work predominantly on GM cars and trucks and they use g/s as do many other manufactures.  I first asked about this two years ago and there still is no resolution. I do not want to have to switch back and forth all the time. This will be my deciding factor in my next scan tool purchase.  Thank you for your time.