It all depends what you are looking for..? If you just need Position, then I would consider the GP330B which uses NMEA2000.
If you want Heading, Position, Pitch, Roll, Etc. and would like to have the ability for use of Radar Overlay (for example, Radar Overlay on a Plotter Screen) then I would then look at using SCX20, which also is a NMEA2000 device.
Thanks Deepblue.
Seems the SPX-20 is back ordered until late September, fishing seasons is almost over by then.
Not sure what the reason was or is, but that's a bummer for Socal boaters and fisherman like us.