Both the Silver Diamond and the Golden Nugget will go long and break hard on the backend. In general, the GN will handle slightly more to a full degree more oil than the SD. In box condition the SD is more for medium-light oil, it will go longer and break fairly hard at the backend, depending on how much "hand" you have. The GN will handle medium oil (for the same person, for the same drilling, etc) but will not goes as long nor break as suddenly, although it will still be very strong. The GN having a light load of particles is more towards a control style, as compared to the SD, while many people might drill it to flip and will be surprised at how strong the GN looks. On its own, it may not look like a control ball at all; everything is relative. All said and done, the GN is an incredible pin mover, one of the strongest I have ever seen.
Both covers are very adjustable, although I wouldn't polish either one any more than they are in out-of-the-box condition. The SD uses PK 18 pearl and is easily adjustable, if needs be.