Well if you gave ME the choice between banging my head and learning the Kanrethad encounter, but not getting any closer to better gear to help me OR stick that same amount of time in running dungeons/scenarios/LFR and get better gear, but not getting experience in the fight, I'd choose the second option. It's easier to learn a fight when you can get some decent damage out to kill the Imps, and more likely, the Felhunters. It's hard to learn when your gear gives you no leeway and every single time you make a mistake you have to start over.
If you are doing it for the challenge then just stop gearing further once you hit 470-475. That's a gear level where you'll still not make the enrage normally and still can't afford any big mistakes, but at least have the damage to get Felhunters down reliably when handled right.