BTDT, alloy frames do not stand up well to high volume shooting that we do in this sport. My first IPSC/USPSA had an alloy frame. I shot it so much the holes where the pins go through the frame became elongated and eventually had to "retire" the frame because no one could do a proper trigger job.
Alloy frames are designed to be carried a lot, not shot a lot.
My .02
Kendall