Personally, I'm not a fan of digital download. After playing through a game, I typically don't touch it ever again unless it's something really special like Super Mario, Smash Bros, or Zelda. So, I sell my games after the first play though. Then I re-invest that money back into another game. This doesn't work with digital only games.
Besides, I never buy games when they come out and it's not like new games come with real manuals anyway. There's nothing to gain by buying new over used. So, I can go on eBay and get a two year old game for $10 whereas it's still $30+ on Xbox Live.