First, the good: some great acting, especially the supporting roles (Pesci in particular, but also Pacino).

Next, the adequate: DeNiro was not as great as he has been, so many, many times before. I'm judging his performance by the standards that he had a difficult task, to convey his character motivations though body language and facial expressions, because he had a ton of lingering shots in this 3+ hour movie, and not a whole lot of dialog towards that end, that was mostly driving plot action (memorable phone call and conversation with daughter near end notable exceptions). Perhaps the message he was trying to convey is that Sheeran was not that interesting or motivated a person, he just did what he was told and tried to (and mostly succeeded in) not thinking about it, but if that was the intent, then I have to question, why even make the movie, especially one this long & this focused on one person's experience?

Now the bad. This movie was in SERIOUS need of a strong editor; vast sections could have been cut out. Understand I'm not saying there are sections that are inherently bad in & of themselves, I'm saying there are just too many good or even greatly acted scenes that are simply just too redundant to each other, or too extraneous to the central theme. The movie was stuffed chock full of "moments," ominous conversations etc that probably would seem great in an isolated clip, but in aggregate bog the pacing down too much. I think less of this indulgence earlier in the movie could have allowed Scorsese to make the climactic action (the last, most significant hit -- avoiding spoilers here!) have the big buildup that he clearly wanted it to have, without having to "dial it up to 11" to achieve that. It's like putting salt on food: if you use it sparingly in general, where it's really needed you don't have to add much to really have an effect. But if you pour salt on everything, all the time, at a certain point if you really want to get that flavor you have to dump a ton on, and it will end up covering up whatever flavor nuance you have. This is what I felt like was happening in the buildup to the climactic moment. Since watching I've been reading about the history of this movie, trying to figure out why there was so little editorial control put on this movie, why no one could stand up to Scorsese to tell him to tighten it up. As far as I can tell, Netflix just wanted the "prestige" so badly that they gave him total control, and, well, while I guess I can't blame him for reveling in that, I think (like most creative storytelling) it would have benefited greatly from a good strong editor, but Scorsese got the agreement to indulge himself from the start (not unlike Jackson with "The Hobbit")

Also "bad" was that was such a literal, true retelling of a story from a book that any and nearly every objective, informed observer knows was a load of BS. Read the article "The Lies of the Irishman" in Slate for the full explanation. Sheeran simply made up stuff in his last months so his daughters could share in the profits of the book that was made from it; his claim he was the hitman in the Crazy Joe hit is particularly contradictory to eyewitness accounts that the real killer was a short Italian guy (Sheeran was Irish & 6'4" ! ). Another example, regarding the FBI agent depicted in the book and end of movie as begging him to tell the story because he was the last one still alive -- well, in real life the FBI agent this was based upon didn't do that, simply because he didn't believe most of the stories Sheeran told. Far from being eager to hear the "truth" before Sheeran took it to the grave, the actual guy could care less, because he'd already figured out it was mostly fiction anyway.