My wife is a HUGE Entourage fan...I'm a bit more casual (I've seen most of the episodes over the years, but was never really invested in the story or characters at all).
So this movie is exactly what you would imagine...like a 2 hour long episode full of the same stuff you saw in the HBO show. It was funny, and charming in the way the show always was...and my wife seemed to really love the wrapping up of the story so I suppose it did a good job in that regard.
Overall? If you weren't a big fan of the show, this is definitely a take it or leave it movie. I kind of felt like it tried to hard to remind you that it was ENTOURAGE!!!! (but it really didn't need to because everyone was perfectly aware of that)...had she not been a big fan, I would have never seen it to be honest, lol!
As a stand alone movie for anything less than a big fan, it was a mediocre raw "comedy" that would probably only be worth view on Netflix one day.