I have a love-hate relationship with this vac. I hate that it is so cheaply made; it is literally a DustBuster on a stick. The filter is difficult to put back in place after you empty the dirt and if you don't get it just right, you can't lock the dust cup back on.  I can't imagine it holding up long enough to need the extra battery pack.  But I love how helpful it is!  I have white tile floors and two big dogs, and this thing makes it so easy to pick up dirt they track in as well as leaves and bits of food they leave behind. My daughter has the Dyson cordless and it is built much better, but it costs 4X as much with every discount and coupon we could find and its function is about the same as my Eureka. I am not sure if there is a happy medium between the two, but I couldn't find one.