well the high performance definitely has the suction - I am still amazed at what it picked up out of my carpet
Both of those vacuums fit all of the needs that you outlined for us. The High Performance has a longer 40 ft cord, multi-cyclonic technology, and a air valve dial on the side for optimum suction power (it switches the suction power from hose tools to floor). The Air however, is much lighter (11-14 Ibs depending on which Air model) than the High Performance (19.75 Ibs) and is better at getting under furniture because of the nozzle design. If you have a thicker pile carpeting or multi-level carpet, the High Performance is for you. If you have low pile carpeting and need the vacuum head to get into those hard to reach areas, we would recommend the Air. Both are good for use on bare floors, have HEPA filtration, great suction, and are very durable. Hope this helps.