We got Heroic Stone Guard down last night on 25 man. Elemental Shaman are pretty middle of the pack on this fight and your ability to perform well will depend greatly on how well your tanks get the two guards together (obviously have to be within CL range to perform well).
The downside (or upside depending on how you look at it) is that our mobility makes us prime candidates for being Vanna White (illuminating floor tiles/can I buy a vowel?). Being assigned this job (as I was) will pretty much destroy any chance you have of DPSing effectively. Of course without us Vanna White's running around, the rest of the raid will suffer so I just consider their bonus DPS as my own! haha
And on a side note, the "You can not interact/click on anything!" bug made doing that job a royal pain in the a$$! "Oh, Cobalt is charging? I will go click the Cobalt Crys...damnit...I can not click on it!" Even better was the attempt before our kill where I could not click on any of them! /facepalm Thank God they are patching that today.
Yeah we didn't really have a set person for dropping tiles, each person was responsible for 10 every reset. The only time that there was an excuse was during non-Jasper chains were players had to stay grouped up. And as for Elemental shamans being mid-pack, I think anything is possible with a ittle RNG and proc management. Yes CL depends on the tanks but at least for 10 man there is only 2 tanks and 3 adds so there will always be 2 stacked. The only thing I had issues with on the fight with the stacked adds was managing magama totem, it seemed that everytime I would drop it the tanks would move just right outside its range.