I don't like the +10 Agility that Corvus armor gives to its wearer. Mainly, because I think the reasoning behind that bonus (a smoother fit of its moving parts) should be better represented as a lessening of some previous penalty (because the armor is lighter than usual) instead of a plain bonus. After all, the Astartes Scout Armor is lighter and "smoother" than any Power Armor, and it doesn't gives any bonus to Agility!
So, in my games, I house-ruled thas the Corvur armor has no +10 Agility, and instead of that, its penalty to Concealment and Silent Move test is -20 instead of the usual -30. I know that this is a negligible advantage, but I think that it better reflects the description of the armor.