Generally I consider the SMAC terraforming system way better than Civ3. In SMAC your terraforming strategy affects your entire game strategy. You have to think! In Civ3 you have to do little more than build farms and mines all over the place without further pause. A boring micromanagement task.
However I agree with warpstorm about the specific terraforming option of raise/lower terrain. IMHO it already made little sense in SMAC, and in a terran setting it's completely unrealistic.