Fire Ant Armor: Sleek vs Bulky?

Was wondering if there was a definitive answer to which upgrade path is better for this particular armor set.

The Sleek version increases acid damage by 10% per piece which is 30% extra acid damage.

The only acid damage as far as I am aware is from the fire ant armor itself, with a 10% chance to proc 25 damage per attack.

So if my math is correct, 25 x 1.3 x .1 is only 3.25 extra damage per attack on average. The Bulky upgrade is just a flat 20% more durability and damage. To me the extra damage resist is the clear winner, especially with slower weapons. A faster weapon may get more procs which would increase the value of the extra damage, but I'm still not sure if it's enough for extra damage to make it worthwhile.

Just want to make sure that my math is correct and that logic makes sense.