Wonderful effect. The only way I can see to improve it would be to use a little more .. (EVERYONE except for Paul turn your heads away NOW) .. saturation. Many of the HDR techniques leave more blacks and greys so cranking in more colour might be something to try after HDR processing. I'm looking forward to trying some HDR things myself. Nice work. (returning to local spell checker ;)
I don't know anything about HDR - so I have no idea how to 'judge' this - it looks somewhat like a painting to me.
Somehow it affects my depth perception(?)Interesting....
Kat
Jimbob