very nice render.. only suggestions i have are presentation..
the image is a bit big even for my 1080p monitor.. still need to save out to see fully. ..posting images that size dimension while sticking with the 500kb limit really does injustice to your renderings. always a best bet to keep the pictures u post page sized.. like less then 1280x1280 proportions. and then include your fully fully full sized render in a fullscreen link. it's easier to appreciate things that way
that said the only issue i can see with your render is on the dragons left wing. to the right of the "talon" or bone fragment in the wing theres an area on the surface that looks like either the bones material is coming through or theres missing textures. other then that everything looks really nice and would probably look better at half the size when the resizing will naturally antialias the picture some more for you.
hey great piece! hadn't seen it until the clay render but I really love the balance between the simplicty of large shapes mixed with really specific detail in areas. Great great!