I think the main issue is understanding how a small-damage power (like a Xenomorph's acid blood, that deals 1d6 damage in an area) is relevant if all the PCs, and almost all enemies they'll be fighting have armor that soaks 5 or more. If the attack doesn't bypass soak in some way (e.g. by degrading the armor over time as the acid eats into it, perhaps), it seems like the players can just ignore it, since it does at most 1 damage to them at a time (on a 6).
There are also exploits like Strafe (and the space combat version, Torpedo Spread) that let you do 1d6 damage in an area without an attack roll, which seem to be similarly irrelevant in most tactical situations. I guess they could be great if you're facing lots of high-DEFENSE, low SOAK enemies, but I've never seen that happen. I suppose being attacked by fighters is a real threat to a ship if it doesn't have any PD, so maybe Torpedo Spread has a use (though it's stupidly expensive in ammunition), but Strafe just seems like its always going to end up being worse than Spray, since there aren't many things with very low HP and SOAK on a human scale (assuming that the PCs aren't committing massacres against civilians).
