To have a plot, generally you need to have an antagonist. I don't think there is an antagonist in Mean Streets, despite what happens at the end of the film (I won't spoil it in case anyone reading this hasn't seen it yet).

It seems like a lot of movies that are based on actual events don't have an antagonist/plot. According to the back of the DVD, "It's a story Scorsese lived." Perhaps the reason there is no plot is because it is semi-autobiography which leads me to the question...which character is supposed to be Martin?

I am pretty sure that the DVD wasn't remastered. I felt the picture/sound quality was the poorest of any DVD I have ever watched.

Mean Streets was made in 1973 so maybe a 30th anniversary DVD will come out with some technical improvements made. I hope so because I thought it was a really good film.