I have the GPS V and like it. Negatives are smaller non color screen than SPIII and no voice prompts. Pluses are it has Hawaii in the DCAs for it while SPIII does not. (or did not when I bought mine in April) GPS V also has a few more add'l features that the SPIII does not. It is also better for hiking. Batteries will last much longer. If the GPS will be strictly for auto use on the continental US, I would probably have bought the SPIII.