Negative Positive
Title: Not "Ultra Quiet"
Review: I have owned a Rabbit Air SPA-582A for three years and have been pleased with its performance. Decided to get an SPA-421A to place at the other end of the larger house I bought to balance things out. I was disappointed upon starting it to hear that its not as whisper quiet as its big brother. The fan motor makes an noticeable oscillating humming noise even on "auto" with the fan running at its lowest speed. When the SPA-582A is on auto it can't be heard at all unless it catches a whiff of dust or odor. Add to that the charcoal filter is thinner and cheaper and I'm really wishing I'd spend the extra $70 for another SPA-582A. Its better (well, at least they were three years ago - hopefully the whole line up hasn't been cheapened).
Is the review positive or negative? 