gtx 260 vs gtx 280 cuda considerations

As far as I can see, the GTX 260 has >80% of # of SMs, bandwidth, and ROPs as the GTX 280. Are there any other considerations which would make the GTX 260 perform less than 80% the speed of the GTX 280 (assuming 896 MB of memory is fine)? The GTX 260 appears to be ~60% the price now, seems to be a bit better in power consumption and noise, though the review sites seem to vary a lot. I am guessing the differences are because of the sites, not the models – correct? They all have the stock fan and heatsink now, right?

http://www.hardwarezone.com/articles/view…2620&cid=3&pg=9
http://www.tomshardware.com/reviews/nvidia…80,1953-26.html
http://www.tomshardware.com/reviews/nvidia…80,1953-27.html
http://www.techreport.com/articles.x/14934/16