1. S-Works frames are the Specialized's top-of-the-line stuff, so I think the E5 is a little better. The difference, however, is marginal and probably near impossible to notice.

2. No, probably not. The 2005 model is probably cheaper because it was last year's model.

3. I believe they are the same frameset, but I've no idea. You might have to ask your local dealer, or go to Specialized's website.

4. Again, probably the S-Works model.

Remember to ride what fits. Good luck!