Man, revisiting it for a transmog run I really have to say that I think Dragon Souls is easily the worst raid in the entire game. It's so unstructured and bland feeling, not to mention it is set in a major location from the previous expansion. Mix in some Thrall-jerking while we play second banana to him doing literally everything of value.... it's just so bad. I mean, I didn't really raid much at the time but I can't even imagine what it would have been like to run that every single week for nearly a year. I was doing that for ICC but... ICC was actually good.
I totally understand why the raids in Cataclysm were not that spectacular - they did a TON of work to remake Azeroth, but still, when something is nearly unbearable to quickly solo, that's a problem!