Angelo, there's absolutely no longer any doubt that some coverts have unacceptably poor accuracy. Nice comprehensive tests, many thanks to you and Tadferreira for all your time and trouble. But which units suffer worse, and why? This has to be somehow related to certain 37xx hw being less/more compatible with 34xx gps fw. Is your convert maybe a later production model, ie S/N 1W80xxxxx, where first x is not 0?