Some of the questions raised here about the new GX2150 can be answered by looking at the owner's manual. While that would seem obvious, the manual is not easy to find right now. As of this date, there is no mention of the GX2150 on SH's website (despite the fact that they've apparently announced it in press releases), and therefore no link to the new instruction manual - until now.
I did some searching around and experimented with manually editing the URLs of their existing owner's manuals, and sure enough I stumbled across the owner's manual for the new GX2150
So just click the link if you want advance info on how to configure the DSC to multiplex with AIS at 38,400 baud (page 83) or set true/magnetic COG (page 21), and any of the other new features of this radio.