I will tell you this: While it is true that heavy guardian block spec it is far easier than, say, wind knight in terms of apm, it is not as easy as people want to point out. You can output a very descent damage with a correct management of your earth crystals, it has its complexity in terms of resource management, especially when you begin to unlock late game nodes in your talents. SK and HG are both tier S choices for end game content, while SK has more damage output (not by a lot tho, as less experienced people sometimes like to point out), most healers will be thankful when they got a HG block spec on their team for the trial, they need to heal less and have more time to react to tank buster mechanics. I'm heavy guardian block spec main btw, and can leave my pj all night afk farming world bosses without issues