Thanks Maddog!
The place is vast and your right it has lots of rolling dunes much like parts of St Anthony in Idaho. From pictures and videos I have seen there are few large dunes, however if you watch the second you tube link it just goes for ever. I don't ride my KX5 in the dunes anymore, it is set up for desert running. So in the dunes I like my 700 V Force quad and my Teryx for long days in the dunes.
The trip I am planning for next May will be Mescalero Dunes ,NM, Killpecker, back to St Anthony, Little Sahara, UT, Sand Hollow, Ut, Cinders AZ, and Hot Well Dunes,AZ. Every couple of years I have to go back to Glamis, just nothing like it for pure grandeur! If I can pull this trip off I will have made it to 14 of the dunes in the US.
Alan