Bob:
I have used B&G as this was the product installed on most Island Packets back in the 90s by the dealers. Today it seems to be mostly RayMarine networks. We do have a RL70C radar / chartplotter unit and we have used this sine 2001 with not issues. Raymarine is great with service when we had our one break down of the transmitter.
I have the B&G autopilot and it has been a real workhorse, I love it. BUT, others have swapped this unit out for the RayMarine autopilots.
So, if all my electronics were gone, I would compare these two companies B&G vs. Raymarine and I would most likely go with Raymarine as the B&G seems to be more racing driven and Raymarine seems more cruiser driven.
Hayden