Wonderfully done photo for the challenge. I wish it were framed with the tree in the middle, more over to the left and some negative space on the right. But thats likely just a personal preference as I dont like centering of photos too much. This is a 7 from me.
I may not know anything about HDR - but this has POW factor as far as I'm concerned. Each range of color is rich and intense. Love the symmetry with the bit of counterbalance with the stump( rock?) to the right. 10