Well if your progressing on gear everyone has to start Heroics at some point. A warrior friend of mine really needed a tank so being hesitant with a PuG I said why not. So we headed to Mechanar to get some Heroic Badges. Me Protec Paladin, a Warrior (Fury), 2 Warlocks, Shaman (Resto). No CC there except for the demons it turned out.
Have run Mech a few times was familiar with the place. But on Heroics I can really tell the difference in being hit hard on Plate. No joke, Heroics do hit pretty damn hard. The Shaman healer is a friend of mine and did many runs with him before and he was also a bit new to Heroics. Think he took a while getting used to healing Heroics so we ended up wiping a few times during the entire run. On Capacitus we wiped once due to the Resto Shaman running out of mana, I could clearly see it as it was happening. Everything hits as hard as a asteroid impact in Heroics. A few times I seen hits on me for 3-6k hits including on bosses.
The fourth boss the Fire Boss lady just sucked, we tried her last and wiped on her several times with all 3 fire elementals running around. Best try we got her to like 4k health and we wiped but it didn't help that the DPS died first and I last one alive when we wiped. The waves to the last boss we had to reset them a few times as someone easily died when they were getting hit and with lots of fire damage that burn hot like sunspots. We wiped a bit learning Heroics. But we did get our 4 badges to stay the least. One the Warlock a clothy was complaining how much her repair cost was going to be. I never said much about that being the tank but I can say my repair cost was over 25g for the run and that's not including all the tanking food consumables I used or including Potions/Elixirs/Wizard Oils. Cloth wearing class can say all they want in a instance but I can tell you their repair is no where in the ball park of what a tank consumption and repair cost is. I go into every instance fully stocked. Often inmost cases a tank cost can easily out cost the entire 5-man group repair bill and if you include all the consumables its a pretty damn high cost.
Never been to Slave Pens before but later with my new guild we ran Slaves Pen on Heroics. That was smoother but we had 2 wipe deaths due to inadvertent adds on the first boss right at the pull and another sometime after that. Most the Naga mobs I just AoE for CC unless the mage had one sheep or rogue had one sapped. The second and last boss we one shot both of those. Picked up some plate gear and epic gem and all 3 Heroic Badges. The gear drop I can barely remember what they were. Was fun. But best I can say if doing Heroics you really need good gear, damn good healer, good DPS and for no one to pull aggro if can help it. CC does makes like much easier. Run a instance your at least familiar with on Heroics. I always prefer 1 or 2 mages in Instances. Melee mobs in Heroics hits real hard its just in my opinion ridiculous the amount of damage they hit for. Well 8 more Heroic Badges and I can get my Libram of Repentance and a few huge repair bills I'm sure.