the idea of filtering is to take unwanted signals out of an image which involves sampling the texture and using the correct mip map. just because ATi is angle independent doesnt necessarily make their filter higher quality.

check this out.
http://www.pcgameshardware.com/aid,6...eviews/?page=5

if anyone with a 5870 would like to make a comparison to nvidia's filter there is a better way.
download this.
http://www.3dcenter.org/download/3dcenter-filter-tester
and this 8192x8192 massive .dds texture then use it in the filter test.
http://www.mediafire.com/file/yizwgmxxbmj/bigtex.dds