It's lovely that they nerfed the packs of adds in LFR that required 15 sec too long to kill, but the DPS available to a typical LFR group is still basically never enough to take Nazgrim down without 1-2+ stacks of determination.
I'm freaking tired of zoning into the instance on the last boss and when I should think "yay, quick 15 min valor!" it's a 48 minute clusterfuckfest.
Just lop 100M health off the dude already and be done with it. What is the fucking point, seriously, Blizzard? The groups don't have the DPS. I don't know why. But they don't.
No amount of setting the bar higher is going to raise the floor higher.