Thank you for your comments.
firstly was shot on 5DII, 4 sets of 3 exposures(+/-1) processed in photomatix4.
why do I do this, well I dont like hdr mode in photoshop.
I feel I have a lot more control here.
once combined and tone mapped, I take tiff back into cs5 (opening as a raw file)
this allows me to process the combined hdr as if it had come out of camera.
in cs5 I work in layers and find tools like colour balance to be invaluable in briging even more photo realism to my work.
once I had processed the 4 seperate hdr's, I stitched them in PTGUI.
hence the 12 exposure, 4 shot hdr pano