Knowing the application in which a vac will be used is key to determining the best one for the job. Hard surfaced stairs with carpet runners will benefit from a vac with both motorized brush head attachments and crevice tools. Adjustable suction settings will add to the versatility of the vac and its abilities to adapt to the different surfaces. Beater bars and brush attachments are best for plush carpet fibers and can really dig in deep to nab all that hides beneath the surface. For applications where there are open railings and raised ceilings, a vac with adjustable extension wands and small accessory tools can really help tackle the full scope of the staircase and its surroundings.