LOL - well the jury will be out soon enough but I doubt there will really be much of marked difference in overall vapour production between the 2 - any difference will most certainly be down to the atomiser and the type of
juice being used.
The only real differences I can see are the switch placement, the fact the prodigy is slightly larger, and the external design scheme. Of course the internal design will also be very different and only time will tell which of the 2 will stand the test.
On the one hand, the large battery (18650) in the prodigy will have a longer run time than the AA sized battery used in the GG.... but on the other hand the trade off will be the larger size that the prodigy comes in at. 2500mah will give you a good long period of
vaping but 900mah (sd is 880mah) is still more than decent for most users.
In terms of the 3V CR2 800mah (GG) VS the 3V CR123A 750-1000mah (Prodigy) well there really isn't much in it - again the Prodigy in this case being the slightly larger of the two....
The rest is down to personal preference regarding style, form and function.