I've tried it on 3 different sites at the same time. For whatever reason I got 3 very different results...Good, Bad, and Ugly. You might also see it display 2 300 x 250's stacked on top of each other in place of the 160/300 x 600 image. If it would collapse to a 300 x 250 when not filled I'd probably use it more. And when it's filled with 8 Text ads it looks terrible IMO.