First of all , about the nmea output -- this unit do NOT output nmea . fugawus support the Garmin Protocol , which be what this use , so there still be software package to use , just not nmea protocol . second , this unit take advantage of auto-routing , so get MapSource CitySelect instead of metroguid . it be pretty much identical to MetroGuide -lrb- street , pous 's , etc. . . -rrb- except it include auto-routing information that be not include with metroguide . overall , it be a great unit for the price -- rugged and feature-full . I would recommend it !