Indeed - those look great!
What are your spec settings like?
I leave them on default, but when I make the spec maps in CS4, I don't desaturate, just go straight for equalize, then I play around with the various filters of the Fade Equalize options, and then I find one I think looks good.
I do rendering in MAX 5 using a lighting rig that TUS gave me. Yes TUS, I know, it's old and outdated, but I applied the Light Tracer and Ray Traced Shadows to the rig. :-D
Anyway, I just attack the spec maps, reduce the lighting levels down, and move the light around and find something I like.