I am very excited at the idea of very very difficult levels which reward better armor. That's something I will be sure to grind for. The question is.. will it actually be hard after 2 weeks when everyone is used to it? I will believe it when I see it. The beginning of hacken ruins was great. People were forming teams, strategizing, etc. Never seen that before on this game and it was a welcome addition. But after 2 weeks people could solo the map that was supposed to be hard for 8 people to complete. I think much of that had to do with leech though, which I think you said you may have to nerf.
Here is my fear: after essentially failing at creating a level that is really difficult for 8 people to complete, you will try to redeem yourself but will go to far. The new levels will be too hard and more importantly, not fun. I trust you when you say how these new levels are really going to test players, but I am nervous that you may forget about the fun factor. I feel that the large majority of people that play this game don't have the patience to fail a level 20 times only to beat it on the 21st try. Especially if the only reward is a box drop, which you might not even get.
I also fear the game will become essentially run by the top guilds. If these new levels really are so insanely difficult, the only ones who will be beating it are the top guilds and their grind teams. You already see guilds nowadays making guild only rooms to grind 8p. Its true that there are many times that open rooms of random players complete 8p, but that's because its easy. 2-3 skilled players and you should be able to complete it. If the new levels really require 8 fully geared pros, those types of rooms wont succeed. I fear a game where to access the games best content you have to be in one of the top guilds, which I think you can agree would be a huge turnoff for players not in those guilds, as in, 90%+ of the community. I hope there are ways for players to get great armor by playing solo too, to counteract this, but I don't have my hopes up.