Here is a class mate of mine, he has downdc every difficulty both old HC and current mythic. He says it's boring as shit to repeat it as well.
http://eu.battle.net/wow/en/character/frostmane/Zeilar/statistic#14807:15164
Garrosh Hellscream (LFR Siege of Orgrimmar)--
Garrosh Hellscream (Flexible Siege of Orgrimmar) 35
Garrosh Hellscream (10-player Normal Siege of Orgrimmar) 16
Garrosh Hellscream (25-player Normal Siege of Orgrimmar) 9
Garrosh Hellscream (10-player Heroic Siege of Orgrimmar) 3
this is just a random guy from a top guild.
http://eu.battle.net/wow/en/character/silvermoon/Khantor/statistic#14807:15164
Garrosh Hellscream (LFR Siege of Orgrimmar)--
Garrosh Hellscream (Flexible Siege of Orgrimmar) 7
Garrosh Hellscream (10-player Normal Siege of Orgrimmar) 6
Garrosh Hellscream (25-player Normal Siege of Orgrimmar) 5
Garrosh Hellscream (10-player Heroic Siege of Orgrimmar)--
Garrosh Hellscream (25-player Heroic Siege of Orgrimmar) 45