I've been having extreme fun in Heroics these days, something I just hadn't done much of since Wrath.
Did a little HoT heroics in Cataclysm, but that was mainly in a push to get LFR Deathwing down.
But now, especially with my Monk, Heroics have been incredibly fun and while at work, I've been trying to think of why exactly that is.
People will tell you that MoP Heroics are "Easy". Well.... yes, they are. However... now that I think about it, I think I get why exactly people say they are "easy". The mobs do not hit all that hard at all with their basic melee attacks -- this puts far less pressure on the tank and healer. They hit hard enough that a DPS won't want to try tanking one, and hunter pets just can't keep up with the damage for long, but yet tanks can be lesser-geared and still survive in Heroics.
In Cata Heroics, I remember trying one as a barely-geared tank and trash mobs were near-killing me on every pull even with max CC used. I ran two heroics with a Paladin Tank who was wearing mostly 450 crafted with a couple 463 pieces. She did just fine, and the healer wasn't super-geared. Heck, one heroic I saw a bear druid with full Dread Wastes gear (not even 450) and he did SM Graveyard all the way up to the monk without dying. He only died because he pulled the monk and 3 of his friends. We wipe and try again, we got that boss down just fine, and then he overpulled again inside the monastery (causing a wipe) and wound up leaving the group. If he had been more careful with pulls, he would have finished the instance with some mild difficulty on the healer's part.
The bosses, however... will still kill you dead with their mechanics. Earlier this morning, I got one-shot by Rattlegore because I didn't notice my bone buff went down at some point and I was running over to get a new one.......and I drop dead. 497k damage done to me. Ouch.
Or the priest who died in <2 seconds because he didn't move after Lillian Voss's mass death grip.
And then, I died yesterday at the first boss of Setting Sun Garrison because I had been Sabotaged and I did a roll to get away from my group members.... only to roll right into two bombs just as mine exploded. BOOM. Dead in an instant.
I like how they made these heroics, IMO this is a much better way to do it -- more focus on working/dealing with the boss's mechanics and less focus on how much gear you have and how fast you can mash buttons and/or ridiculously tight mana conservation for healers or Wrath's "Healhealhealhealhealcan'tstoponesecondhealhealhealhealhealheal" model they had going.
So... Kudos to Blizz on this one. Great work! Hope to see more of it next expansion.