(please note that I've been running it on midgard only, so my experience only covers that)
As a quick introduction, I just wanted to state that I've been running HoH since its inception and went from liking it to finding it rather boring when done using the latest midgard-pbaoe group composition.
When we first ran HoH on midgard, we used trolls to kill things, that's what they're good at after all
Then, considering there was no CC, we decided to try to pbaoe them, and things went south fast.
Trash pulls became considerably easier, and some boss mechanics could simply be ignored.
I'm thinking about the brothers here; they were a great fight, with good coordination required and all, and
suddenly became pushovers.
People started to even push the idea further going with more and more pbaoe, up to 5 SMs and using a... skald (!) to tank.
We went from speed-runs lasting about 40 mins to runs below 30 mins with little effort.
That was bad; instance became too easy, and I fully agree that some balancing was needed;
because it didn't become easier only as we learnt how to do it better, but because we found a way
to bypass some of the mechanics through sheer damage.
Now onto the current state of the instance.
Beluna: wasn't changed, was actualy one of the hardest to do with pbaoe groups.
Brothers: wasn't changed, still piss easy with pbaoe. the real change on this one actualy comes from the enhanced HP on tanks that makes healing the 95% gaze harder.
Halgartha: quite harder; doable with pbaoe, not sure how that would fare with a melee group (aka would the melee be able to kill adds before they heal the boss).
(for that one too the tank HP boost is actualy nerfing us more I'd say as the healer has to pump a bunch of power into the group after the culling)
Maschunga: bit harder; doable with pbaoe, not sure if melee would be able to cope up with the HP up of the adds (probably).
Mother: wasn't changed. why ? she was already by far the weakest of all. I even tank her with a 2H so my healer doesn't die of boredom. we killed her with only 5 persons and probably can with 4.
Szregoo: became super hard, even with pbaoe - I barely see this guy being killed with a melee group w/o using some advanced form of kiting, was that the point ?
Ogoga: lightest change I'd say; still largely doable
And now onto my conclusion/observations/suggestions.
I believe the real balancing that was needed was to prevent the instance from being farmed so heavily using pbaoe groups (at least on midgard).
But the changes you decided to implement don't solve that problem at all imho; they make some of the bosses pretty much impossible to kill with a more classical melee setup, which means people will simply have to use higher realm rank pbaoe or completely skip some bosses, as most groups already started to do.
One change that I believe would have been more efficient and probably not so hard to do is give all bosses and possibly all trash some form of resistance to aoe damage; hence negating part of what makes the pbaoe so stronger than anything else.
For the brothers, you could also make it so the troll doesn't simply unspawn when Zorsch dies; that might be enough to force people to actualy play the (nice) mechanics you created for those guys.
Though that is unrelated to the current changes, one other thing that was slightly 'abused' is the character change for Ogoga.
As the Ogoga fight was rather annoying to do with pbaoe, most groups swapped pbaoes for melees.
That probably should be blocked one way or another (such as locking the instance to a given character/account pair).
As a last note, I'd like to say that this doesn't reflect my opinion only, but that of several friends I've been running the instance with a lot.
Please, think again about those changes, and do something 'better' than the current state.
Thanks for the hard work, Skal.