As another new homeowner (at age 55!), I bought the M17 with the leveling feet and am so glad I did--I've already used it outdoors on uneven ground and indoors on stairs. LOVE. IT. For me the M17 is tall enough--I have 12 foot cathedral ceilings on my main level, and only have to reach gutters at 8 feet. Allison Koster Moorhead, MN