I'm going to play through the entire Myst series. I've played the first two games before but then stopped because Myst III & IV were not (and still aren't) available digitally. I've recently aquired them used and they work. So before I get to it: Where does Uru fit in? It came out between III & IV but I've read it takes place between IV & V. Since I've only played the first two games I know nothing of the plot in the other games and if Uru has any relation to them at all.
Simply what would be the best experience in terms of plot and/or gaming?

Play URU after Must 4. Things in URU are relevant to Must 5.