I hate vacuuming stairs. It's so clumsy to do with an upright vacuum, and seems slightly dangerous to me. That's why I use one of these. It's super easy to handle, and the brush guard flips around 90 degrees to get the rise of the stair. Granted, it's not going to have the power of a full vacuum, but it does a decent job even in a condo with two cats who freaking love the stairs.
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Matt