I love him! I might actually steal that idea for a model, the hood and the 'Nid head work so well! Ramp up the damage and spread for the shotgun in that case, you want those few rounds to count! I think this model is really missing a left sleeve though, a missed oppertunity!
I do think that he needs a melee weapon though, a big nasty chain weapon like the beastly Inquisitor-scale chain axe or an ork choppa, something he can stick through someone's skull when he runs out of shots!