Guys --
The G2 and GB Pro with 11" DD coil are the SAME UNITS! Dave J. says in his sticky that the "frat bros." DD coils are appropriate for this machine -- either the G2 OR GB. If you buy a G2, it has a different rod/handle, and slightly different faceplate than the Gold Bug Pro; it comes stock with 11" DD coil. If you buy a Gold Bug Pro, you will get a 5" coil, but like with the G2, will have compatibility with the "frat bros." DD coils. If you buy a Gold Bug DP, you get the 11" DD coil instead of the 5", like you do when buying a G2 (the DP unit is simply a Pro, but comes with the big coil, not the little coil). Basically, if you look at the rod/handle setup on the G2 versus the Gold Bug Pro/DP -- and find that you like one better than the other, then buy it. Otherwise, you can't go wrong with either. They really are the same machines, just variations on the aesthetics, the rods, and the coils included.
Steve