I guess I am happy with the FITech, but this is an instance where you get what you pay for...There is a complete lack of documentation, and no information on the tuning software. For some reason mine did not include the drivers to connect the handheld to my PC, and they haven't been able to send this to me after 2 months of back and forth.

The handheld unit has a 3x3 matrix. It does interpoltae between the 3x3, but one thing I don't like is the breakpoints are 45, 95, 180kPa MAP. So for a NA engine, you have only a 2x3, plus an "idle" point

I had read somewhere that in the PC software you could modify the base fuel/spark tables which were supposedly 10x12. I have found the breakpoint definition arrays for spark and VE, however, I have not been able to find the Spark and VE tables that correspond with theses breakpoints. They have 4 different cam settings, each with its own ~9x9 VE mult surf. Once I drove around and collected some data, I started modifying the VE mult surf by the long term fuel adaptation to get the base surface closer. I am +/- 5% fuel trims now, where previously it was correcting up to 30%.

I think they system is plenty capable for a basic TBI retrofit, but it sounds like they offer no advanced tuning support. I think the intended market is essentially they guy who bolts on the box stock carb, is too lazy to get it tuned correctly, gives up and thinks EFI will solve all his problems.

Another complaint/comment, is the data logging. it has pre-loaded data log windows, and you can only record the 20-30 channels in that window at any time, you cannot record everything at once.