It's Ennis's only Nick Fury series not published under Marvel's MAX imprint, so it's toned down a bit. There's no stomach-turning sexual content and the swearing is only PG. Damn, hell, bastard, bloody, etc. No F-bombs or worse.
It is, though, reasonably good. It's a World War Two story, which is very Ennis.
Fury's with the US army shortly before the Battle of Kasserine Pass (which really happened and, yes, the Americans got their arses handed to them as Ennis describes). Fury ends up wandering in the desert. His life is saved by a German lieutenant-general (to Fury's irritation) and by a group of SAS irregulars. He eventually makes it back to London and on to an assassination mission behind enemy lines. A surprise is waiting for him.
The big question, of course, is "why Nick Fury?" Ennis has written lots of war stories, some of them better than this. (There's nothing wrong with it at all, but Ennis's war stories can be superb and I'd describe this one as perfectly normal for him.) He clearly has a soft spot for Fury, but even so is there a reason for this specific book beyond "a WW2 story that might sell"? The answer, actually, is "yes". In Ennis's MAX stories, Fury misses war. He enjoyed it. He lives to fight. He doesn't know what to do with himself when he doesn't have a gun in his hand. This story's built around that, from Stephen Barkhorn's early advice to the big question where we genuinely don't know how Fury's going to jump.
The tone is realistic and pretty good. It doesn't feel toned down, unless perhaps you've been reading lots of super-sweary Ennis recently. Anyone used to Marvel war comics is in for a shock. Fury's definitely not heroic, being a brutal soldier who's keen to kill and might be tempted to make horrifying decisions.
It's worth a look. Ennis does WW2. He's done it before and he'll do it again, but that's because he loves war comics, knows the history inside-out and is very well suited to it. The story's big question makes things unpredictable. You'll get more from this if you know Fury and/or Ennis's take on the character, but that's not necessary and I'd just as readily recommend this to newbies who've never read a Marvel comic before. Violent, satisfying and mildly educational (as history). Thumbs up.