Is mantle convection theory as good as we can get? Can it explain the variation in the world's divergent plate boundaries? The depth of the Mariana trench? The Basin and Range area? The San Andres fault? Current and past mountain building mechanics?
Please visit my "Plate Tectonic Mechanism?" thread in speculations and tell me what you think.
I have been quite busy writing a hypothesis concerning the thermal heating of the planets that possess magnetic fields and the several moons that exhibit the early development of these electro-magnetic phenomena that in the Earth's case I believe drive the various geologic processes that are currently observed and debated.
You can view this work;
http://electroplatetectonics.weebly.com/ is the Earth's geologic processes as seen through the thermal forcing of a variable electro-magnetic field.