Also, when I vacuum a throw rug, I lift the front end so that I can come back over the rug without the rug lifting up or getting the fringe stuck in the roller. Plus, if I need to go from a carpet to a throw rug - you have to actually LIFT the whole vacuum to make the transition. If your throw rug has fringe, lifting the front of the vacuum and pulling back allow you to have all the fringe laying flat and beautiful.
The other reason I like a lift, is if there are leaves on the floor, popcorn, cereal, bigger debris - I don't have to use the hose. I can lift the front of the vacuum and pick it up - so much faster and easier.