All the modern, plug-and-play EFI systems are good. Mass-flo's system uses a mass airflow meter, as opposed to a manifold absolute pressure sensor, to control fueling. This is an inherently better design for self-tuneability; it requires no re-mapping of fuel or spark curves, and self-learns at a faster rate than a MAP-controlled system can. It is also less sensitive to component changes; a differet intake manifold, headers, or a camshaft upgrade seldom requires any more than a few minutes of driving it to re-learn the fuel curves, so it can use the new parts to their best advantage. I am not knocking the MAP systems, just expressing my preference for the MAF system, and why I like them. I haven't used any of them, but I read about them, and wish I could afford it. You pays your money, and you makes your choice.