Ok, let's strap in.
I'm pretty easy to please when it comes to films. I live 5 minutes away from a nice movie theater; I'll watch anything from He Named Me Malala to Furious 7, and usually come away pretty satisfied. It's hard for me to not like a film. Even stuff like Transformers 3, which was a stupid ass movie, has something that appeals to me, like the absolute carnage that happens in Chicago.
For Suicide Squad, it's pretty easy to recognize the flaws in it, but to me, it was a ton of fun to watch. And it was never boring; something that basically every movie this summer totally fanned on.
It's a loud movie. All the character intros are extremely colorful, full of bombast, and do a pretty decent job on filling us in on the backstory (though I still would've vastly preferred these characters to show up in previous movies, but alas). They felt well thought out, and for the most part, all had hooks to them.
The action is OK. I generally prefer WB's way of shooting films over most studios, so they're still quite on point there, but it could've been better on the action front itself. The movie shines the most to me when they're focusing on the core concepts of either the Squad (bad guys forced into doing good), or the characters themselves. My favorite scene wasn't even a big setpiece or large scale battle (two things that I'm unsure as to why the movie needed them), but a small bar scene. Banter between extraordinary people is still intriguing to me.
I don't really think there were any misfires, casting wise. Will seems back in leading man mode, though I probably would've preferred more of a focus on him, to be honest. Margot is excellent, pretty good emotional anchor. El Diablo's subplot is solid. Boomerang and Croc seem like they're there to troll, which is fine. Katana didn't do too much, and neither did Joker, which makes all the heat about the latter seem kinda dumb. Your highlights are probably Harley/Deadshot/Waller, in that order.
I tend to view critic reviews as one part of whether I'll like a movie; most of them don't share my tastes, so I'll mostly just use them as a barometer for what kind of a movie I should expect. Personally, it feels like they're taking Squad to task for flaws that they let slip by on earlier comic-book films; endless army, unnecessary save the world plot, that kind of thing.
I'd say Squad starts off well, stumbles a bit in the middle, but gets to the finish line in a solid way (probably due to the reshoots). It's a fun ass movie. Perfect for a matinee if you're bored. It feels like more the product of people's hype being deflated versus the actual quality of the film itself, which is no more egregious than most summer films.
Me? I'll go watch it again tomorrow. I'm a sucker like that.