I'll try to answer your question ....
For the 10D sensor which captures 12 bits of data per RGB channel, you get 4096 levels of light (per channel). Let's say those those 4096 levels are distributed acrosss 6 exposure zones (approx dynamic range of the CMOS sensor).
Use a modified Ansel Adams system. Call the darkest portions Zone 1 and the lightest Zone 6. Zone 6 has two times the light of Zone 5, and captures (or quantifies) 2048 levels of light. Zone 5 has 1024 levels, Zone 4 - 512, Zone 3 - 256, Zone 2 - 128, and Zone 1 - 64. Thus you have many more light levels to work with in the higher zones, and you can achieve smoother gradations of color and contrast as you remap these levels during image editing.
Suppose you have an image that has only 3 zones. If you set your exposure to capture those zones as Zones 4 to 6, then you have 3584 levels of light intensity per channel to work with. If the same image were captured in Zones 1 to 3, there would only be 448 levels. So it would make sense to capture your image in the higher zones, and then make levels/curves adjustments that re-map your levels to other zones. Further, the claim is made that the signal to noise ratio is better when exposing to the right.
If this concept is correct, you would have to capture the RAW image data with exposure biased to the right. It wouldn't help try to re-create the expose to right bias after that image data is already imprinted on the sensor.
Because 12 bits gives of color information still gives a lot of signal levels, even in the lower zones, I'm not certain that this theory has practical consequences. However, I do find that color corrections and adjustments are harder on underexposed images compared to those exposed to the right, assuming that in neither case do you have blown highlights or blocked shadows.
Note also that once you convert the 12 bit image to 8 bit, you are now working with 256 rather than 4096 levels. If you don't first edit in 16 bit mode, the penalty for not shooting to the right should be even greater. So in principle, a JPEG image from the camera would benefit even more from exposing to the right. (Redo the math on the above 3 zone example using 256 rather than 4096 levels).
As a practical matter, many avoid exposing to the right for fear of blowing highlights in one or more color channels. Some images cover the entire dyanmic range of the sensor and can't be exposed the right. Some settings give you no choice but to underexpose (for instance, when you need a fast shutter speed).
I try to expose to the right, but I don't find many real world senarios where it is feasible to do.
Hope this helps.