The Beretta is about as reliable as a pistol can be. It is more reliable than the M1911. That is not a criticism of the Colt as it is famous for it's reliability, but the fact is the Beretta has done better in tests conducted by the U.S. military.
The Glock would have been even better, but it wasn't entered:
the revolutionary Glock 17 pistol was withheld from the U.S. XM9 trials at the behest of its inventor, Gaston Glock, who would not accept U.S. government requirements to release the winning contender's production and patent rights to open bidding. The Glock pistol represents an entirely new era in small arms technology. Glock would have submitted his pistol only if guaranteed production rights. However, this stipulation does not conform to procedures practiced by the DOD.
The best choice would be a small-caliber handgun with 3-shot burst capability, like a Glock 18. If our soldiers aren't allowed to use hollowpoints (does anyone think the Taliban follows similar restrictions?), the 3-shot bursts should do enough damage to drop enemy targets. The low recoil of the Glock 18 in single-shot mode would allow soldiers to use it easily with one hand.