I'm glad you like it!

There is some posterization in the belly area - the noise in the shadows is just too much to really find a lot of detail and it looks pretty grim without some noise reduction, which made the belly into kind of a grey smear. I think in a larger crop at common print sizes it would not be a problem. Another possibility is to darken the belly a little more, to make it less apparent. That might be the best way to go.

The background needed a good jolt of noise reduction too, I would suggest exposing a little brighter on ISO400 shots - they will be much cleaner with a better exposure. Noise dwells in shadows, and a perfectly exposed shot will ALWAYS have less noise than an underexposed shot at the same ISO. Otherwise, they do all contain a ton of detail and will probably make nice prints once they have been processed. Especially with digital, post processing is an important part of the process. These days it's just easier and cheaper than it used to be.