I think you've done some nice work here. The conversion is neat and the painting seems ok but its hard to tell, the pictures seem to be letting you down. With a bit of work on your photography skills, I'm sure you could bring up your scores.
Keep it up! :)
A really good conversion, I never imagines what the Chaos Spawn could be good for. But I think your mini lacks some bronze, so it doesn´t look very khornate.