When I use my SB-600 off camera, I ALWAYS set the flash to manual and start at 1/4 power, and than go from there. That way, it's more like studio strobes. i-TTL sometimes complicates things by metering every time, and although it's consistent, I lose that much control everytime. It's also not that big of a deal to shoot in manual because I can control the flash power from my camera.
So, with the total control I can get from my camera, putting the flash at a distance where the inverse square law works to my advantage, I can get great results.
This for example was done with one SB-600. The 600 was the key light, and I used the sun as a kicker, even though it looks like it was another strobe, it wasn't!
I put my SB-600 to 1/2 power, and my camera to 80mm, f/4, ISO 200, 1/500th. At half power, I was able to get my strobe far enough away to where the lighting was even all across her body and still provide enough light for a proper exposure, with f/4 I still got nice DOF, and my ISO at the lowest to be clean. 1/500th is my max flash sync.
All of this was done using Nikon's i-TTL system, no pocket wizards, no radio anything, just the flash on my tripod, 8 feet away, and my D70's flash popped up as a commander.
This is why I encourage off camera flash as much as possible, it gives amazing results with ease when you learn it.