Why? For the past few years, the AMP!'s received positive reviews and seem to be one of the best in terms of price vs. performance, especially where I live (Canada) since they are usually <50$ more than most reference cards.
PS: I have never owned a Zotac card since they usually take too long to be released here and I didn't know about them when I purchased previous cards in 2012 (MSI 680 4gb) and 2010 (Evga 480 SSC). I have a MSI Lightning 780 now (purchased used from the forum for almost 200$ less than a new 780 in Canada), but plan to get an AMP! next time.
PS: I have never owned a Zotac card since they usually take too long to be released here and I didn't know about them when I purchased previous cards in 2012 (MSI 680 4gb) and 2010 (Evga 480 SSC). I have a MSI Lightning 780 now (purchased used from the forum for almost 200$ less than a new 780 in Canada), but plan to get an AMP! next time.