I agree with both. As I am riding down the road under normal circumstances I do prefer to hold toward the center line.
At left turns I take the entire lane. I even do this in my other vehicles as well.
There is a spot close to home where there is just enough room for one car to squeek past another if the lead car is over left. Regardless of what I'm driving...my bike or my truck pulling a trailer...I hold to the right so none of the clowns get the idea to try and pass