Furor and Kitty dps

So Furor is a nice little talent: I have 2/3 in my 60 cat druid build.

When soloing elites/groups, I tend to slap mangle+tf+bleeds, and Rip procs Predator's Swiftness.

So I pop into caster by instacasting Regrowth.

When I go back to kitty (two gcds [~3s] later), having about 10 energy going into caster form, I find that I've got 70 energy. Standard regeneration rate (unhasted) is about 10/s. For three seconds of ontarget dps downtime, I get double regeneration rate.

So my question: if I specced 3/3 Furor and used it as a cd during white damage only periods, would that be a better use of the gcds than waiting? I'm thinking mostly of burn phases: XT heart, Yogg brain, PP p3.