They say the insides are the same. I guess some of the earlier G2s actually said GB on the screen when they were fired up. The two, when bought new come with different sized coils. The Gold Bug comes with the 5 inch and the G2 comes with the 11 inch. I knew that I was going to cover a lot of ground and trusted the iron separation enough to want the big coil. I went with the G2 for that reason. You can go to the websites and look at the mounting differences. How the box is mounted and what the rods look like. I can't see either one being a deal breaker. I like my G2. I am mostly hunting farm fields and old house sites. I wanted it to test it in iron. You have to force yourself to aim right at the worst of the iron to truly enjoy the benefits of the G2?Gold Bug. When the other detectors swerve away from the iron you have to charge right into it. Be prepared to dig some very small targets. I don't mind digging these tiny things. I say it is really good practice for those $1 gold pieces we all want to find. I hope I helped a little. I am sure other people will chime in with their thoughts. Either way you can't go wrong.
Don
HH