Philippe,
I have played PD and BD and will play Sand Hills this week for the first time. Pacific and Bandon have a very different feel to them, in my mind.
Pacific Dunes elevation works up and off hills - the climb to the 2nd and 6th green, the tee shots of the high points at 14, 17. However, Barnbougle's elevation changes through the dunes seem grander, though I would be interested in whether there was much difference in total elevation.
Both are tremendous pieces of property, among the finest modern properties I have seen. In terms of quality, I found both to be similar, with different pros and cons for each. When I played Barnbougle in Nov/Dec of last year, the fescues were very thick, which perhaps took away from the fun a little bit for others, but did not bother me. I imagine the grasses will come into their own over time.