The main benefit (other than ease of use) of the AVGA is the fact that the boot/POST screens are 15khz, whereas they are VGA when using Soft15khz. I'm also having some problems with certain resolutions missing in Soft15khz that work fine in the AVGA. But I'd say that if you have a card that has all the resolutions available with Soft15khz and you don't need to worry about the boot screens, then Soft15khz is just as good or better IMO.