Not so much watered down, as utterly destroyed. I'm seriously disappointed, I was only able to get Killer Prime because of Frozen Wasteland, and now other players are going to struggle even more than I did.
The Madness drops still worse than the original Hard drop rates, given the SoT costs. From a few hours testing yesterday, it appears some of the drop rates from the original Hard were transferred over to the new Madness. For example, the Cosmic Evo Runes, which was a 75% chance in the previous Hard, is roughly 75% in Madness, and to compensate, it's been dropped down to 33% in the revamped Hard. Perhaps if the cost was 15 SoT, it wouldn't be so egregious?
Idk, it's possible this dungeon will still be useful for players who quickly need to get some Red, Green, and Purple evo bricks, or need a couple of cosmic evo runes. It'll become a niche dungeon, not something to eagerly look forward to with future Skull Quest events.
Yeah, the dungeon is a permanent addition to the game, but they keys are event-limited. I'd assumed this was how they justified the good drop rates, as you couldn't buy more keys like you can with other dungeons.