I'm going to say what's happened to me and what it makes me feel about personal loot but I completely realize this is rng and usually not likely the case, but I've gotten 3 upgrades from heroics total with personal loot, I almost never get loot from something that isnt the final boss, and when I do, its a piece I already have. Its extremely frustrating to do a 30 to 50 minute heroic depending on derps in lfg and then get rewarded with an amazing 11 draenic dust from disenchanting if I'm lucky. I just want to get the gear to raid and I have gotten almost nothing useful whatsoever.