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I think it's hard to compare the two since the Road Pilot is a dedicated speed warning system which incorporates radar detection systems. TTGO uses a database overlay for the map which is compiled by users like you and me so the accuracy of the data is not guaranteed 100%. but when you consider the prices then it seems that the TTGO is better value since you get a complete nav system. I suppose it depends on how serious you are about avoiding speeding offences
