Stone Sky Sea is a great tool! Unless you're a dragoon. You can't efficiently practice your rotation as a dragoon there because there's nobody to tether. Whoops. So it's not even a tool to practice your rotation unless you spend Ghysal Greens to have a chocobo sit there and be tethered. But that breaks the dummy entirely since it's not balanced around Eye of the Dragon; I killed the v4s dummy with mostly 320 gear, unmelded, and with the Susano weapon because of it.
It's also worth mentioning that the dummies were never rebalanced for any buffs or nerfs. To kill the v4s dummy as a ninja is an accomplishment of luck and gear power, since it was balanced before the gust slash nerf came out. So even then, the dummies no longer tell you if you're putting out enough to beat a fight.
That aside, the SSS dummy remains a static dummy and, like everything else regarding parsers, has not only been discussed to death but dismissed to death. It doesn't show you what combinations of your party / GCD placement in certain places grant you the greatest returns in a specific fight.