OK here is my lil test.

I made a quickie model (excuse the texture) this morning.  From left to right

No Bump or Normal Map
Bump Only
Normal Only

The model was made in 3d coat, which auto generated the Normal and Bump map at the same time.

I rendered with the default bump value of 0.08 but the bump map hardly showed up, this one is with a value of 1, which shows up some details as well as the Normal Map (also value 1) but distorts other parts too much.

As I said I don't know the full mechanics of it, but I am very happy with the results with the Normal Map :)

John

Fugazi (without the aid of a safety net)

https://www.facebook.com/Fugazi3D