Usually, we 3-man instances, and we did plan to do so for the Wrath, but a friend leveled up and wanted to join us, so we're now 4-manning the Wrath of the Lich King dungeons. We started with Utgarde Keep, the nominally 70 instance, but when we moved on to Nexus, we actually found it much easier. Utgarde was doable with 4 except for the last boss which is just not tuned for your run-of-the-mill level 70 tank, and requires much more timing and precision than any pre-70 instance bosses. Frankly, I expect to see the final boss of Utgarde nerfed in the near future. Nexus was another story. It was fun, fast and furious. It changes so much through it different sub-zones, and you really have to learn the instance to do it well.
The final boss of Utgarde Keep is Ingvar the Plunderer. He requires precise timing and a very good tank (or one that out-levels the instance, i.e. is above level 71). We, sadly didn't have a great tank... we had me. In 6 tries across two runs, we failed to take him down. In the end, our problem was timing, and some of the problem might simply be lag. I'm tempted to go back again and do it without using my wireless network, and see if some of the problems go away, but our last attempt should give you a sense of the problems we had:He has two phases, and in the second phase, he does about 15k damage with an AoE cone strike in front of him. He takes about 3 seconds to cast this strike, so your tank needs to notice the cast bar, run through him, and wait for the cast to complete before running back. He won't turn while casting the strike. We did well on phase one, but as phase two began, he cast a small AoE, and I got confused, thinking it was his big strike. I ran through him, and he turned to follow, facing our dpsers. As soon as his AoE began, it locked him in place (the reverse of the strike), and so he kept facing the dpsers even as I tried to turn him back around... 3 helpless seconds passed and he began casting his big strike, still facing the dpers. It was over. Both dpsers were one-shotted and we wiped.
The timing and lack of mistakes required on this level 70 boss in the nominally easiest dungeon of Wrath was surprising, and really worried us in terms of how hard the rest of the expansion would be. Nexus dispelled those fears. Other than some tricks from Ormorok the Tree-Shaper, the dungeon was quite easy, and lots of fun. The constantly changing environments were a breath of fresh air after Utgarde, which is really just Ramparts with a bit of the inside areas of Dire Maul thrown in. We cleared the instance slowly, not quite knowning the tricks and best paths. I think the boss we killed first (Anomalus) was actually supposed to be the third we encountered, but no matter, we did well and had a lot of fun.
If these dungeons are a sign of things to come, I am really excited about Wrath dungeons. Sure, we wish we'd been able to 4-man all of the bosses in Utgarde and not just the first two, but we're really enjoying the ride, and hope to share many more of these runs with you as we progress!
I don't expect Utgarde nerfs. I might hope they'd make it so he faces the tank while casting the roar, however. It really is about response time (which is of course the combined lag + your own ability to respond quickly) and not gear. Seeing that they didn't nerf this kind of thing out of previous instances, I don't expect them to here either, but who knows.
One problem you didn't mention was in our first series of attempts I somehow hadn't realized that I could avoid being silenced by just not casting during his roar. It was an awful lot easier without a 9 second silence. (The roar is the small AoE you mention, by the way. He casts that in both phases, usually just after the cone strike, but at other times sometimes.)
The cone in the second phase was hitting you for 9k. Remember, I healed you through a few of those. =)
First phase it hit for a lot less (4k? 5k?). Certainly after we got you uncritable.
To me, it felt roughly equivalent of what Ramparts felt like when I was running it for the first time (on my holy pally, back just after BC came out, in bit of DS1 and quest greens). Though there it involves everyone having to not mess up, rather then just the tank and the healer.
Both instances were definitely easier then the easiest heroics, and maybe easier then some of the harder regular 70 instances (I'm looking at you Shadow Labyrinth).
I'm not sure if you've ever tanked Murmur, but it involves running away from him whenever he casts sonic boom and running back before he AoEs the entire party down. It doesn't even give you a cast bar... you have to either look for an emote or the graphic effect on the ground*. If you're at all slow off the mark you can easily wipe the party. Being a pally tank really helps here 'cause you can bubble through it if you realize you're not gonna be out in time. A lot harder to pull off the bubble trick in Utgarde though, as melee will be in range the whole time and could be one shot if you didn't cancel it in time.
* Melee has to do this too. In heroic, everyone has to stay in melee range when he isn't sonic booming. I can't tell you the number of runs that have failed due to healers or ranged DPS that couldn't run out. Or wins where it was me, a rogue and the healer, with our hunter and mage dead. =p
PS Just went and checked Murmur on wowwiki again, I'd forgotten just how devastating Sonic Boom is:
It damages for 90%-95% of your current health (modified by stance multipliers) plus an additional 12% of your maximum over 6 seconds, and applies a debuff that reduces movement speed by 90%.
What's more, now that you've been slowed by 90%, if you can't get back in melee range he'll start using Resonance: Applies a debuff to all targets that increases Nature damage taken by an additional 2000 for each stack, while also also hitting for 2000 base Nature damage.
And now I wish I could edit comments. The first sentence of the second paragraph should read:
One problem you didn't mention was that in our first series of attempts I somehow hadn't realized that I could avoid being silenced by just not casting during his roar.
Also wowwiki makes it clear that Murmur is a lot easier for warrior tanks since they can intervene their way out of Sonic Booms. Though I've never actually seen a warrior tank do that, and I've done it with an awful lot of warrior tanks. =p
Amusingly enough, we always just punted the running around on Murmur, and instead healed through it. Of course, it didn't hurt that we had a T4 priest healing and a shaman throwing a backup heal when needed. Nor did it hurt that, for the time, our dps was above par.
I suspect that eventually, people will just say, "LF tank, Utgarde, 73+" since out-leveling the instance is easier than finding someone who has low latency AND good reaction time (not to mention a clue).
It's funny you say that... now that you do I do remember people insisting when I was tanking that just healing through it was the best choice. That never actually worked out for me, but when I was tanking I was there on heroic.
Most of my time there on regular was a healer and let me tell you, BC Paladin's, no matter how well geared, just can't heal through it. Without AoE heals it's just not possible, IMO. With Beacon of Light, I dunno, maybe. (If you had a party where the tank was the only melee that might also help*.)
It doesn't help of course that Paladin big heals are gratuitously expensive, where as they're actually the cheapest heals a priest can use.
* Then again, if we only had ranged dps in Utgarde then you could just eat the cone strikes and it wouldn't matter, as ranged doesn't get hit by it. So you may just as likely see: Utgarde LF2DPS, NO MELEE!