EVERY hm is a challenge if youre too stupid to learn game mechanics. You wont even beat BT hm in full Dread Guard without knowing game mechanics, Yadira is gonna own you everytime with her cyclone smash!!! LOL
Actually, most HM fps are quite easy even without much knowledge of the mechanics. I generally tank them on autopilot, unless we have undergeared or new players along. None of the mechanics were like LI pre 1.4. Unlike other fps, LI requires the DPS to actualy do stuff other than just mash buttons from weak to strong mobs and watch their feet. For pugs, if you have dps (esp mdps) that aren't use to that, its a big challege to get them to be coordinated. It is simply a failing imho of the fp progression system, because for most of the game you can get past most challenges simply by over lvling/ over gearing. But with this nerf, I think (hope?) that pugs will be able to do it easier and I will get my weekly done without resort to grabing guildies.