TLDR; Whether you liked Army of the Dead or not, if you liked Deiter's character, it's worth a watch.
I was skeptical of this film being good because even though I absolutely loved Dieter in Army of the Dead, I didn't think there could be enough of an entertaining backstory. I was wrong.
Matthias Schweighöfer, who played the lead of the charismatic and likable Dieter, not only gave a thoroughly enjoyable performance as we explored his origins, but he also directed it? According to IMDB, this was his 6th directorial role but you'd never think so because he crushed it. The entire film felt class from a cinematography and filmmaking perspective. It was funny all the way through, too. Storytelling-wise, it thrived without any zombies scenes in his path and instead made the journey of safecracking surprisingly entertaining and not at all mundane as I was concerned. Good on both Matthias and Zack Snyder for the team effort here. Also really enjoyed the other protagonists, too, as they all had entertaining roles within the team.
Comparatively speaking, I think I liked this prequel more than AOTD because of how much I enjoy Sebastian/Dieter as a character.
Side note while we're at it, how in the world is this man 40 years old? He looks like he's in his late 20's/early 30's. I'm shook.
I'm impressed on many levels by Matthias, kudus good sir.