i use flip for mac for client preview and it works great. however, imho, quality is based on length of project. typical example, i have a two minute piece my client wants to preview for content. Not being a compression master or anything, through trial and error, the best looking preset made a very nice wmv file 9 mb long. most mailboxes seem to reject files over this size so thats my target. sent the file, he loved it, on to the next project:)
approach for my website clips is obviously a little different, but i will pretty much approach it the same way.
i think this all goes the way of the dinosaur if i pay for the flash video converter:)