This tier, Furty is maining a Shadow Priest (and he'll take over our Shadow Priest soon), but also plays many of the other classes (including the ones he writes about) in the guild's alt runs, which are still much higher level than most hardcore raiders in lower guilds can experience. He has access to all of the internal theorycrafting they do in top guilds like Serenity (which are basically 20 players playing the game full-time and spending all their time playing and theorycrafting to be the most competitive). He's less wordy than Azortharion or even Wordup (who writes Havoc Demon Hunter, and Arms/Fury Warrior), but his guides are good nonetheless. He has a different profile, that of a hardcore raider in Serenity, one of the best guilds out there. On the other end of the scale, there are our guides written by Furty.
His dedication and versatility (theorycrafter + top raider) does show in his guides and they usually get a lot of praise, but they are not perfect and do get some amount of criticism, some of which is valid and prompts us to make corrections to the guides. He previously raided in Danish Terrace, but decided to raid in a more modest guild for Legion in order to focus on guide writing. For example, our Hunter guides are written by Azortharion, who is both a theorycrafter and an accomplished raider. We agree that some guides go deeper than others.
We just thought we'd share a few words to give our opinion on the issues you raised.