Here were my two primary information sources when I was trying to puzzle out my design:
Step 1: A bit of background
In reading about Square Foot Gardening and the wicking beds, both sources indicated that having uncompacted soil was desirable. In my mind, not adding the majority of the water on top of the soil seems like a very good start in keeping the soil uncompacted.
Another tidbit that came up was that of nutrient leeching. One of the claims regarding wicking beds is that because the water is largely contained within the raised bed. Because the overall direction of flow is upward, the watering action does not flush nutrients away from the garden and out of the soil (as run-off to nearby streams or else just out of the cultivated area). I'm not sure that this would be a significant effect within the time frame that I am expecting to use this system, but it does seem like a realistic concern, especially in the case where the installer has to spend significant time with soil ammendment to achieve good productive soil.