(I have not read all the posts - someone might have ask the exact same question. Here it is again then.)
I really enjoyed the danger element that the hard Bosses introduced. Whenever I do a mission (solo or team), I have to look carefully before jumping into the room, to locate any bosses.
The bosses borderline too hard, but it feels like a real accomplishment when you actually arrest the boss in the end. Even more so than the Archvillians (which requires a team and 5-10 mins of repeated attacks), because a boss can anywhere at a time and place where you were not expecting it.
Sometimes the boss is just too hard, either for just yourself or for your team, especially in the lower leves (<25). As mentioned, the choice of dropping the mission or doing it at a "lower" difficulty must be present.
Now here is the thing:
If you give us the active in-game choice of "no bosses at default reputation" and "bosses at higher reputation", then why cannot the harder boss changes stay?
Why remove both the boss difficulty AND the boss presence?
Also, I think the biggest grief players have with the hard bosses is the number of generic bosses you can encounter at once inside a mission. It is probably triggered by the number of heroes in the team. At a certain breakpoint, you start getting not just a generic boss in every group, but even two and three! In a larger room, you could be facing something like SIX bosses at once. That is just way too much. A single boss, or maybe two, is enough to make things interesing. As is it, trials like the Respec is very hard if not near impossible unless you got the "perfect" team.
So that is three things I want:
1. Keep the hard bosses.
2. Give players the choice of either dropping boss missions or doing them at a no-boss reputation.
3. Prevent multiple genric boss spawns within a certain area.