It is true that Guild bridges are thicker than the bridges on other brands. However, Guild made the bridges to fit with the rest of the guitar's design, not because they were too lazy to carve a smaller bridge, or because they had an excess of wood lying around. The height of the bridge indirectly helps define the string break angle, and that break angle is what determines how hard the top is being driven. The amount of force driving the top is a key determinant in the thickness of the top, and how big the soundboard braces are. In the case of the D25 in question, the braces and soundboard thickness were designed with the knowledge of what break angle could be expected (also implying how hard the top was being driven). Varying away from the designed thickness of the bridge will not allow the guitar to have the tone that it was designed to have (reduced bridge height and reduced saddle height result in reduced string break angle and reduced forces driving the top). In addition, the bridge thickness is also designed to allow for proper support of the saddle without allowing it to tilt forward or back. Sanding of the top of the bridge reduces this support, and further opens up the possibility that the bridge, over time, can crack at the bridge saddle slot, due to the reduced strength of the bridge and the shallower saddle slot.
Kostas
Kostas