I prefer McKee's technical system over Weston's. For some reason I think it is fairly easy to follow and I like the systematic approach that it uses. McKee gives very direct way to write its characters and how to disect the script into beats. For instance, McKee says the protagonist is a willfil character, has a concious desire and several other traits. McKee also talks about working a script from the inside out. We do this in order to find the center of of each character. To build scenes, McKee says we must break open the branches of reality in the gap. The gap is the energy of the story.
Weson wants you to get deeper into the characters. I think it would be a harder way to write, but you would have a complete understanding on why your characters would do and act the way the do. Weston always wants the reader to have questions about the character.

1. Is it possible to combine both methods?
2. Which previous script does Sex, Lies, and Videotapes style of writing compare to?