Don't underestimate the mitigation that comes from Rooted's regen bonus, especially when Earth's Embrace is active. I put 2500 or so hours on a Stone/EM tank back in the old days, and re-rolled him as Stone/Spines on Homecoming. The only time I turn on Granite is for major AV fights, or things like the Nictus ambush in the ITF. The rest of the time, having almost 3400 HP and regenerating 70 or so every second, combined with Rock Armor/Stoneskin/Fighting pool, is enough.
I don't bother with Brimstone or Crystal at all - but I slot the heck out of Rooted and EE, and built for perma-Hasten outside of Granite, to keep EE's health bonus up as much as possible. And I built to soft-cap psi defense with Minerals up (which isn't hard...), since there's nothing more embarrassing than a granite tank getting smoked by a bunch of Wisps or those floating idiots from Praetoria. I don't think I've turned Granite on at all in a Shard TF.
I'm also a fan of Teleport. Shift+LButton is my best friend.
It's a playstyle difference, in the end. You can definitely build a stoner to take advantage of def/res set bonuses. I just feel like the mitigation is good enough elsewhere, and there's enough Leadership floating around on any given team, that using set bonuses to counteract -spd, and give +regen, +HP, and +recharge, is more fun for me.