Sal - yeah, we thought the same, I think they said it would be 3 months before they needed to be changed...uh not quite! lol I found the suction does get affected by the bag being half full lol

But having said that, I LOVE it, DH - not so sure - he hates having to change it to a barrel vac to do the hard floors, I don't nind, find it easier in fact. But it has paid for itself twice over already (we have had it nearly 5 years) just in cleaning the carpets - our RE agent couldn't tell the difference between Kirby clean and Steam Clean rofl.