I agree both the pack and the mask look very good, but don't think it is more difficult than human face.Look at the articulated individual finger tips on the hellgast. Look at the buckles on his packs. Look at the details on the helmet and face mask.
I was particularly referring to edges of fabric clothing where bump-mapping fails (in any game).
edit - and as per the new E3 rules, guys, be very careful about name-checking games in your comparisons. Generalise if you can.
What rules? No comparison?