Onlyindreams, Kham meant he was going to add 12 of each specific eater type for his armor pieces + 2 kinetic 15's so when he equipped his wall of hungry mouths shield he would cap each of his elementals at 30, and have his kinetic at 30.
Kham, a lot of the samps on my shard throw a shield in hand for down in lower Shame since they generally only run 60 parry. They don't really care about not being able to parry with a shield in hand. Keep in mind, if you're being cast on continuously, you won't get your life bursts back until you get a minor pause from taking damage. It'll save like 40 charges (I think it's 40 currently) of those life bursts. Personally, I like it if I get overwhelmed, and need to peel off redlined. Then you see a big benefit. My samps are mostly all throwers now though, and I don't rock dci, so sometimes during a spawn level bump, it can get a little hairy, and the burst helps.
I wouldn't bother to get 30 on each eater Kham. If I were you I'd much rather go with 2 kinetic eater 15's, and rock your shield, rather than waste a mod on each piece of armor. The 20's across the elementals from the shield are more than enough imo. By the way, kinetic 15 on a piece will count as 90 intensity points when imbuing.