Certainly the use for PNG24 in IE through the Alpha filter gets a bit limited and you will have to size the area that contains the transparent PNG accordingly. The Alpha Transperency filters are not of much help either. Usually i end up using “scale” as the sizing method.
Sofar it has proven good and i have been able to provide PNG24 transparency for client projects that way.
Transparent PNGs in Internet Explorer 6 by Drew McLellan