I’ll add some additional thoughts:
I find the mode to be hard, but not in an overly fun way (the same problem encountered with weave).
Let me clarify using a comparison with versus, which I’ve been enjoying a lot:
To paraphrase FS: “the challenge comes from having to fight more clever enemies, not more enemies”: in versus ambient enemies are negligible, the challenge comes from the players:
I think the success of this idea (well, for me) is that it uses what I call the VT1 route: fewer enemies, but each one is a threat. Heroes have limited ability and somewhat clunky weapons.
What we have in VT2 and DT is the opposite: heros are very powerful, well-oiled death machines, and the chief way of challenging players is overwhelm them with numbers.
Now, as annoying as they are, Havoc’s hidden modifiers are a way of challenging this premise, making enemies tougher, faster, a bigger threat overall.
The problem, as I see it, is that havoc piles everything together, doing player nerfs and enemy buffs while increasing the intensity at the same time. While this makes sense for the absolute last ranks, I think the mode would better serve as a fresh challenge if they would alternate missions were the difficulty is due to increased spawns - like multiple simultaneous monsters or the tox gas condition- with missions where the difficulty comes from reduced hero power/increased enemy and ambient danger - for example deadlier ranged enemies and darkness or ventilation purge.
The absolute mayhem that ensues when you pile everything together, that is to say: the current state of Havoc is something that requires the strictest meta builds if not overly cheesy strategies: which is precisely the problem weaves encountered, and that’s part of the reason why that dead mode is almost universally considered unfun.
Moreover, some of the modifiers kill careers almost outright, further restricting the meta, and that would be acceptable only in very few puzzle-like missions, and only if advertised, not hidden.
Ammo nerf is a prime example of this.
Pus-hardened skin (like the rampart mark from CW) is the most misguided of the mutators and the only one I would remove, doing what Nurgle’s blessing already does, but worse.
TL;DR:
Hero nerf runs, in dangerous maps? Sure, cool!
Op enemies? Bring it on.
Bonkers spawns? Yes please.
I can’t be the only one that loves fighting a lord and a beast at the same time.
There’s a lot to be lauded about havoc, and I think with a rework - or if it allowed players to choose their mutators - it would be universally loved.
The main problem it currently faces is that it does everything at the same time.
That and that it does it in a frame - matchmaking, ranking - that almost nobody asked for or wants.