Just watched 12 Rounds 3 on Amazon Prime Instant because I'm still on Labor Day vacation and it was there. It's not completely abysmal, just Die Hard in a police station. Ambrose didn't have a ton of dialogue to mumble through, which was for the best, and the CGI blood made me chuckle. Not a recommend, but it wasn't boring as all fuck like the first one (never saw the second one) and definitely won't be showing up on anyone's bad movie night list.
That said...I haven't actually seen a ton of him in the ring (not since his days as Jon Moxley), but I really don't get the appeal of Dean Ambrose and I never did. But what I have seen of him, his ringwork is sloppy, his offense looks like shit, and his promos are cringeworthy (so basically, standard PG-Era WWE).
His offense looks worse than his ring attire (seriously, that slop-tacular rebound clothesline he does 15 times per match and always looks like it's done in slow motion) and I absolutely despise that lame, affected Roddy Piper voice he uses in his overly scripted WWE promos. You know, there are a handful of wrestlers who break out into the mainstream like Cena, Lesnar, the Rock, ect. But it's pretty safe to say that Ambrose will never be one of them. Sorry if you're a fan of his, but the dude is fucking corny.