I bought a Raymarine EV-100 wheel pilot so I can spend my time trimming sails single handed, and I now I'm having to deal with the stupidness that is SeaTalkNG.
SeaTalkNG is nothing more than typical NMEA-2000 with stupid proprietary connectors that make almost everything harder. They decided that they could include one extra wire and then it would be somehow backward compatible with SeaTalk (which is their proprietary connector and bus version of NMEA 0183).
With SeaTalkNG, cables only have female plugs and T-adapters only have male. Also, they've switched the position of the rotating lock-ring from the cable to the device. These seem like good ideas (you can now get the cable through a 7/16ths hole vice 9/16ths) and you only need female terminators, but the lock rings are terrible (they're quarter-turn locking rather than screw-down) and you now cannot create a backbone by chaining T-adaptors together, you either have to have a small cable between them or you can use a proprietary mini-backbone device that Raymarine devised to solve this problem. These cables are all at least $20/each, so every little bit of added complexity is an annoying extra cost.
But the biggest problem is that SeaTalkNG to NMEA2000 adapter cables don't seem to really exist. There's a part number, but I can't find it for sale anywhere. You have to cut and splice a SeaTalkNG cable and an NMEA 2000 together to adapt the two cable systems.
So I'm designing my system so that it's NMEA2000 on one side and SeaTalkNG on the other, necessitating only one adapter cable in the middle. This means I have to do two backbone runs--one for NMEA 2000 devices and one for SeaTalkNG Devices. Or I can hack up all of the SeaTalkNG cables and convert one end to NMEA 2000, which will look nicer but cost about $120.
Sorry about the rant, but it's just really disappointing to have all the good work of a single standard messed up by a big vendor for no good reason.
Fortunately, Garmin makes a field-wireable NMEA2000 connector you can use to easily adapt SeaTalkNG cables to NMEA 2000:http://www.westmarine.com/webapp/wcs/stores/servlet/ProductDisplay?productId=435902