I wasn't the tank, but the healer, in the group I was in.
My only problem with the playtest in general was how many raid geared, myth'd and fabled folks I saw in the gathering spot. I saw so many full VP sets and myths...Aeralik himself was in the Warlock fabled suit with the Warlock myth, legendary and fabled jewelry. He also was pulling in high end folks, those mastered out and with high end gear.
I just have to wonder just how balanced of a testing is all this? Espcially since Aeralik wanted us to go thru "easy TSO instances".
The above folks testing out easy instances is like testing performance on a high end racing car and then using that data to evaluate the performance of an economy car.
The average L80 isn't going to be in raid gear. Maybe a few masters, a fabled piece here and there, but they'll be in legendary from RoK and whatever they get in TSO.
I dunno...it just seems like the testing will give results not indicative of the general player populace. I find it hard to believe that raid geared toons are the majority. Testing really shouldn't be based on them, no offense meant.
Of course, there's always the devil's advocate view: working with what you have...as in most who copied over are raid geared and mastered.
I dunno...but I just had to say something, not really meaning to argue...just had concerns and not sure where to put them.
And before I head off...Kiljoi, Ardor, Carainy, Dread, Sharp, Odonox (sp? and they left in the middle of testing)...it was fun, really. And Dread, don't forget to keep your evac away from your fighting hotbars! 
Its easier to pull aggro when the whole group is well geared, as there is a lot more stuff currently out that boosts dps than boosts tank threat.
The difference in taunt abilities between a fully mastered raid tank and and adept3ed legendary fighter, isn't actually that huge either, so my opinion is that lesser geared groups should find it easier (except for the fights being longer). Of course I haven't actually got a group on test as a tank to test this theory.