Well, it depends on how much you're willing to spend. New Kirbys go for like $1,000 more or less, but you can get used ones much cheaper. How much does this Sebo cost vs. the Kirby, if you don't mind me asking?
I've never had a Sebo so I can't judge it, but my oldest Kirby is about 31 years old and it's still going strong and picking up exceptionally well, so that should kinda speak about their quality.
