I have been working with these paints professionally for over a year and absolutely love them. Note that "roller marks" are every painter's pain. Here are a few suggestions to alleviated the edge (overlap) lines:
1) Apply a same-color base coat before starting 2) Roller the paint in X and W and V patterns (not strictly in straight up and down patterns) 3) Apply a minimum of two coats over the base coat (each coat evens out the coverage and the use of a same-color base coat doesn't allow for much contrast behind each roller stroke) 4) Realize that wet and dry paint, side by side, will look like different colors but they should dry to the same color (with the exception of the Ralph Lauren glazes which are very, very tempramental.) 5) Keep a wet edge. If you must stop before you've finished the entire room, try to stop in a corner, or at least smudge-in a wavy, non-harsh edge wherever you decide to leave-off for the day.
These painting problems are most noticeable when working with deep, rich colors (like so many in the Ralph Lauren line)that are applied directly over white or light-colored base coats, so use your same-color base coat first, or stick with the whites and neutrals (noticeable errors).