I've discussed this issue on another website. One person there had some good points about showing full scenes in the reel. He was basically saying that the people who hire directors and editors generally have to be fickle. If you don't show them exactly what they want, then they'll move on to the next reel. They want to see the scenes to judge a director's ability to get the performance and they want to judge how an editor has good rhythm and knows when to cut.
He thinks that the montage type of reel works well for visual effects, DPs, color grading, etc.
So... I'm going to redo my reel that I just posted here.
Stephen Eilers
Director - Editor - Visual Effects Artist
Please comment on my reel at
http://forums.creativecow.net/readpost/173/857874