He is turning out quite nicely! I really like his head and collar. I am not too sure about the stormbolter though. I feel he would look much neater with a smaller sidearm. As it is now I feel your eye is drawn more towards that massive weapon and less towards the rogue trader (also I feel he would have trouble wielding such a massive weapon). Looking forward to see where you go with him. Keep up the good work!
I agree with adam - the basic model is great but the weapons look rather heavy handed. Id go for a pistol of some some exotic design (perhaps xenos" and a sabre style power sword. A powerfist is a very blunt weapon for a rogue trader.