The single stack gun is preferable to a hi-cap for an all out steel gun because of the potential for lower weight (perhaps a tossup with the STI/SVI polymer frame) and more importantly, mag function. The mags on the hi-cap guns have had a tendency to feed a little slow due to the large, heavy column of rounds they must push up during each cycle. The lightened slides that make fast steel guns cycle extra fast. The combo of extra fast slide and extra slow mag feeding makes for a lousy marriage. I know this well, as I tried using a super lightened slide on a Para .38 Super to shoot IPSC major.