That remaining 10% is when I have found a group in matchmaking, we actually load into the game with no issues, and we can complete the mission.
Other than that, there are major balance issues that are making the (group) play experience, not fun. It is important to me for these elements to be fixed, because I am only tolerating the single player. Id much rather play in a group, and will spend the majority of my time trying to do that. With that said:
I understand there is supposed to be some difficulty with certain enemy types, but there should also be some equivalent exchange of gun fire and knife fights that make sense.
Fighting a Lemen Russ makes no sense, their damage output is too high, their (and several other enemy types) health regen too robust. The imbalance makes for a negative experience.
Fighting Orgyns is a drag. One is tough as it is. Fighting more than 2 with shotguns kills the experience. Fighting them with mobs aggroed and I just quit the session.
Fighting mobs period is a coin toss. Not totally a bad thing, but for the amount of time it takes to connect to a group, the 3 death limit, and the fact that as much as I like this game, I have no qualms with putting it a way for a while makes facing Martyrs challenges, a challenge in of it self.
Improvements have been made, but there are still some basic, core elements that must be fixed. A lot of quality of life improvements, and a LOT of fine tuning on engagement varieties.
Again. I don't mind hard/ difficult... Just don't waste my time.