I have to give a thumbs up for this spec! I've been messing around with the Storm+Mit builds since hitting 50 and although yes, incendiary round does make for some good DPS I don't think it at all makes up for the survivability. In my opinion it makes for far more fun and in your face gameplay by going up tactics.
Stock will typically crit for 2200-2600 / High impact crits for 1800-2100 and ion pulse crits for 1000-1200 / Explosive surge crits for 1000-1200 all depending on relics and buffs(mind you this is typicaly in full supercommando champ gear with crit/surge relic). It doesn't sound like much but with gut dot and ion cell dot it makes for very respectable TANK damage.
After Hitting 50 i messed around with builds but quickly fell back onto something very similar to this build and have stuck with it right up to rank 59. It's a very different playstyle from any build that uses assault so I can see it's not for everyone but if your into Guarding and harassing enemy caster this is an amazing build
mind you there are 5 ways (between stuns, Storm, Harpoon, and Riot) to ruin a casters day! If you really want to annoy them go get yourself some crafted grenades too!