VFX & animation showreel storyboarding, session 1 (three hours)

What is a showreel?

For the visual effects and animation industry, a showreel these days is in my opinion very much like a CV, or at least an important extension of it. To further increase my understanding of what a showreel means to successful studios today, I did a little research.

Google returned an About.com article with a nice list of visual effects demo reels to take a look at:
http://3d.about.com/od/Computer-Animation/tp/20-Mindblowing-Studio-Showreels.htm

A few ideas popped into my head from watching these.
The standard three to four minute length of these showreel examples seems a little long for me somehow. I'm not sure what exactly bores me. The content changes very quickly, and I am left with a feeling that I can't focus on anything before it's gone.

I'm thinking could the showreel be shorter than this, maybe two minutes in length but at the same time be more coherent rather than just a random mix of video flashing by the viewer's eyes.
How can I differentiate my work from every other showreel already out there?

Story-wise, things to consider from what I saw was timing, consistency and tact. My showreel should be well structured and convey a simple, effective story.

How can I amaze the audience visually on the showreel? This question is probably the most important in the making of a showreel. I want a feeling that sticks. I'm thinking variety should be evident like in a traditional showreel to keep the interest and communicate that I am capable of working with multiple styles.

Technological expertise should come across with appropriate titles when the focus shifts from, say, animation to visual effects. The software might be good to point out as well.

Finally I figured it would be important to grab from these examples some clues of what is on demand of the industry these days. There seems to be a repeating pattern of particle effects and motion tracking in visual effects showreels. These tasks are both resource intensive and difficult at times so it makes sense to have them in a showcase. Mechanical transformations seemed to be also popular a theme within the selected works. So ideally all these would have to be included into my showreel to make it convincing, right?

Anyway, I'm still behind my set schedule. I will have to ramp up my daily hours next week to catch up. Let's see how it goes.