This is a movie that quite unfairly gets shit on (mostly by critics), as most of the DCEU movies have. That said, it is not a perfect movie and would have been better (I think) if they would have stuck to director David Ayer's vision and not tried to make it a clone of Guardians of the Galaxy, and just had a bunch of misfits that quip at each other.
The story is that ARGUS, headed by Amanda Waller (played wonderfully by Viola Davis) forces a bunch of inmates, some with metahuman abilities to covertly battle threats that the government cannot handle, knowing that the government can disavow them and throw them under the bus if things go sideways. And, to force their cooperation, nanite bombs are implanted in their necks, in order to kill anyone who wants to try and escape. The movie is set after Batman v. Superman and references Superman's death, and Ben Affleck does have a couple of cameo appearances as Batman. And, the movie does do a bit of setup for the Justice League movie.
The movie is mostly an origin story for the character of Harley Quinn (played by Margo Robbie) and to some extent Deadshot (played by Will Smith), and partly a mission story of the team trying to take down a 1000-year-old witch (played by Carla Delevingne). The team is headed by Special Forces officer Rick Flag (played by Joel Kinnaman, best known for the series The Killing), who tries to keep the bad guys in line. The movie also reintroduces the live-action Joker, played by Jared Leto, whose take on the character was totally different from any prior version of the character. Almost a punk rocker version of him. Leto was apparently pretty crazy devoted to the role in real life and did a very good job being psychotic.
The big controversy over the movie is the extensive reshoots that WB forced Ayers to do to make the movie more like an MCU movie. His version would have had much less comedy, no pop songs, and would have been much more of a dark drama/action combination. After the Snyder Cut of Justice League was actually released fans are now clamoring for an Ayers cut of this movie. Whether it will actually come to pass, remains to be seen.
For those who get the Blu-Ray, the movie looks and sounds great in HD. There are over an hour's worth of extras including several making of and behind the scenes features and a gag reel. Definitely, a lot if you like going through the bonus material. There are also two cuts of the movie, the theatrical version, which clocks in at just over two hours including the credits, and an extended version that really just has some extended scenes in it, that adds about 12 minutes of footage.
Overall, the movie is much better than it was made out to be. I do think WB would have been better served to follow the MCU format of introducing the main characters in stand-alone movies before they got to the team-up movies. I think this movie would have worked a lot better if there was a stand-alone Batman movie that introduced this version of Joker and Harley Quinn in order to set up her capture, and then had the Suicide Squad movie be a follow up to that, instead of just throwing a bunch of new characters into a movie that only fans of the comics or Batman the Animated series would be familiar with. That said, it is still a good movie that could have been great if the studio would have left it alone and let Ayer make the movie he wanted to.