I am no expert but from reading what Garrett has available it looks like they are the same but the Gold version has extra electronic features that enhance the detector for searching Gold. As for giving it a edge to hunt Gold, I'd sat that depends on the user and that dedication she or he has to it.
The coils' fit of the electronic "Q" factor of Electronic circuit inside the Dector housing is what makes the real difference I am told.
The Proper balance of electronic parts used betwen the Coil belanced against the sending and recieving resistance of the circuit used: ie: ( The Inductance and capatance of the coils balance against the resistance of the electronic sending and reciving circuit that makes the less internal resistance to the detected signal.
That makes it a balanced system or "Q" point as engineers say. They try to find the least resistance point that gives the best transfer of signals between the unit and coil and thus making for a clearer path for a signal. From there companies add damper or exciter circuits, to increase and or dull down the signal affects depending on conditions and outside factors
Each of the systems use as diferent approaches to features, depending on the quality of the components they used to produce them- The Bells and Whistles or the Bling that makes the costs rise, dont be the best quality so be carefull.
Like i said, I am no self proclaimed expert. But I have come to know that price is "not" a good indicator has to how good the dector is! Nor is how many extra buttons they have, or how fancy a read-out it has. if the Q or balance is poor, the extra features do not do much to improve the syatem.
So...Try them out first-then buy one, is the best advice I think. We will find a Lot of hype from makers, and not much truth is ramped in the advertising.
So- try them first- rent or burrow one if you can- then drop good monies for one. Being in a Detector Club can assist in that also.