The Shark Navigator Lift-Away was the first vacuum I had purchased as I was fortunate to have a central vac in my previous house.  When I went to friends or relatives, I used their vacuums which were much too heavy. I also referred to Consumer Reports.  
I had three requirements:  lightweight, powerful, and a lift-away.  The vacuum performs well on floors and rugs.  It is easy to switch between each surface.  Last, it is easy to clean.  The parts remove easily and can be rinsed out in a sink.