Week 3 in Hellfire Citadel brought me 2 heroic kills to add to my 12/13 normal kills and although the DPS requirement is clearly tougher, it wasn't too bad.
Archimonde, on the other hand, was a different story.
Stand too close at the wrong time, you wipe. Stand too far at the wrong time, you wipe. Stand in fire at the wrong time, you wipe. Don't stand in portal at the wrong time, you wipe. Don't interrupt, you wipe.
I have now done a few PuGs on Archi with raids of varying ability and have to admit that the fight is well designed as a final boss... by which I mean there is very little room for error.
I also experienced something that I can't remember experiencing for a very long time, if at all - I got kicked from a PuG for being the lowest DPS.
Not running a DPS mod, it took me by surprise until I looked at the logs and discovered I was the lowest ilvl as well - apparently 694 isn't fantastic for doing the last boss of HFC, which I suppose is understandable considering you could have had higher with heroic BRF and crafted gear.
This week I'm starting the PuG grind a little higher at 697, including a new gun, so hopefully I'll look a little better in the gear stakes. Not quite as high as the group I got kicked from - most of them were >700 - but at least not "fresh off the BRF boat"!