Oliver,
All of the above posts give good options but they leave out the one key factor... THE CUSTOMER.
Ask you potential customers what *they* think would be best. forget about YOU and what YOU think (even what we think) and ask your customers what THEY want to see. What hat questions do they have. What answers do they needs, what doubts etc.
Once you have this information THEN decide which is the best format to deliver the video in.
The thing is... there *is no* best format...
It all comes down to the best way to deliver the answers that your customers need.
Paul Barrs