I use the SDS EM4-6F and datalog using the Innovate LM1 with the LMA2 RPM converter. Have no problems with the system. Currently datalogging, AFR, MAP, RPM, TPS, IAT and EGT. Seems to work very well. The whole setup was a little expensive, but I still don't have to have a computer (laptop) in the car to make adjustments, can still tune on the fly, and can study or print out logs after runs, and like I mentioned, don't have to worry about a laptop flying around or taking up space. Just an idea.
Warren