Seems so. I managed a couple on last DT hard rotation (got stuck on floor 69, stupid Siphis+Cardinal wave...), but it was really just getting lucky with the first few of them happening to match up to the champions I had built.

I believe so. This is why I don't like this part of doom tower. These rooms require us to "waste" resources on champions that we will mostly likely will not be use anywhere else in the game. 

 It's definitely the endiest of end game content right now. I can only get part way up Doom Tower Normal at the moment and that's fine, I just use it as a place to farm forge materials that help me in CVC and the champion fragments are cool, too. I can do enough to complete the advanced daily quests so it's providing more rewards there as well.

It's not so much the difficulty that's the problem. I'm more than capable of advancing through the regular rooms in DT hard. The problem is the absurdity of the requirements. Beating those rooms with all force ATK champs for example - like, not only are force ATK champs pretty bad at crowd control, they're also up against teams that are very strong to begin with.

I'm just waiting to find that room with the "only void rare champs" or some other crazy restriction like that.

 I'm at that room right now and stuck because all my decent void rares are supports. :-)

 I like this kind of content because it gives a purpose to champions that might not get used otherwise. After 3 months of playing I already have all the champions I need to clear all the dungeons, UNM clan boss, etc. Without things like Faction Wars and Doom Tower Secret Rooms my account would be static as soon as I was finished building the champions I have. I would like to see more events and challenges that require specific kinds of champions. For instance a new campaign for commons or a something like a clan boss but only for uncommons would be awesome! It would make champions that are otherwise just food into something useful and encourage more creative team building.

I can see your argument here. People wouldn't build any new champs at all without that kind of "artificial" limitations, once they have their teams for every area. 

But on the other hand, they should announce the secret rooms earlier, so people have a chance to prepare. It's so awkward if you enter a secret room with double limitation of rarity and affinity or faction (only epic orcs or stuff like that) and see that you have no lvl 60 champ fitting. But that's the way Plarium informs the playerbase about content anyway, not only in Doom Tower. Like the last special rule Spider tournament, only epics. It was announced a day or so before it started. Of course I can build a whole team of new lvl 60 champs in one day, while the Vlad event wants me to do Ice Golem at the same day.

 The Spider tournmanet worked out pretty well for me. Most players in my group didn't even try so I just spammed a lower level of the dungeon with epics I already had and got some relentless gear for my efforts. Because I'm using Artifact Enhancement and Dungeon Divers to finish Vlad I could skip Ice Golem and still progress in the fusion. Suprise events like this seem good for end game players but can also help younger accounts like mine if you're lucky enough to be in a position to do well in the event but most in your group aren't. I have never even checked to see if there's a list of all the Secret Rooms but at least with a permanent-type event you have plenty of time to prepare.

Yes, they are very late game things. Post Arbiter, post Faction Wars late for some of them. Some are well beyond my current roster for sure.

They are ridiculous, I guess that'll be my next hurdle >.>.