Depends on what you are going to do with it. I am moving to EFI this summer so I wanted one that had an output I could use for engine management. I went with the Innovate MTX. In the year I have had it on the car logging and helping with tuning, it has been great. I have been able to chart the changes in gasoline formulations, carburetor adjustments, etc. Now I have a baseline to reasonably judge the EFI changes and what they mean.
Craig