I think its very important to point out/reiterate that lead shot should not be used with GB off. The 30% does affect the dots and that is a very nice size chunk of dps over 30 seconds. A few quick tests showed that stance dancing for lead shot/ricochet, I can do about 20 more dps over a 3 min parse. At ilvl 172, no food or party buff, GB always on averages around 860 and stance dance around 880.