I am learning a lot--very fast about electronics. We recently had our boat refitted, and part of the refit was electronics. The trick is to get Raymarine to talk to Garmin and Furuno. Each company has its own language. Raymarine has Sea-Talk, and Garmin and Furuno use NMEA 0183 and 0180 and 2 000. We started to interface all the instruments, and were fine until we got to the autopilot--which is Sea-Talk and will talk to NMEA 0183 but will onlu do so with Version 2. Our Garmin GPS is Version one and will talk to Sea Talk, but talks too slowly, which makes the new autopilot respond slowly--not good. The pilots on this forum can relate to this because they deal with Avionics all the time. When I flew, that was true as well, but to a lesser degree. We did not have GPS then. In Navionics the GPS is central, and everything evolves from that.
I would be hesitant to buy a GPS made in China--although most of the cables and fittings on our all new Garmin instruments are made in China. I like Garmin for their customer service. When the GPS turnaround happened some 15 years ago, GPS units made by Trimble, Northstar, Magellan, and others, all needed to be sent back to the factory for recalibration. With Garmin, all it took was a toll free call. We were instructed to write in all our waypoints and then enter a numerical sequence on the keyboard--and everything was recalibrated. The Garmin cost a fraction of what a Trimble or Northstar cost. Garmin is a proven entity.