Well, here's another religious argument, I think. Seems there are those who really believe that fitting the bridge to the radius of the top is critical, and others who don't. Pretty clear to me it works either way.
Me, I like to glue a flat bridge down with a fair bit of clamping pressure. The bridge is pretty stiff overall, especially in the center. The top, however is rather bendy, even with a solid bridge plate glued there, so it flattens out easily to conform with the flat bridge with a flat caul under the bridge, and some nice clamping pressure.
Here's the religious part for me: ALL the force on the bridge is from the pull of the strings, which tend to bend it upward into an arch, so I figure that extra bit of tension I may have introduced when I clamped the top flat will actually help the bridge resist deformation.
Here's the secular part: It's WAY easier to use a flat bridge. . .