I started with a Vornado 733 and I loved it. There was another heatwave coming so I ran to Best Buy to grab a second one, knowing that if I ordered online it wouldn't arrive before the heatwave. Best Buy didn't have any of the 733 model, they had this 660 which appeared to be newer & a little nicer. It said it moved the same amount of air so I grabbed it. It definitely looks nicer than the 733, and I think it's a little quieter. I like the buttons being on top and the ability to postition the fan using the metal sliding arm instead of being forced to choose from the only three positions offered on the 733. BUT. I don't feel like the 660 puts out as much air as the 733. The 733 is a powerhouse. And the 660 is too. But put side by side, I think the 733 puts out more air. I put the 660 in my bedroom & the 733 in my living room since that is the larger space. So it works out okay. But I do sometimes wish I had not jumped on the 660 & just waited for a 733.