The Marine Corps knows what it wants, especially in the SOC arena.
Gus's input about how the process works is great. Sometimes, especially when things are designed by a committee, you end up with something that looks like a duck-billed platypus as the old joke goes. This is true even within a relatively small, tight organization like the Marine Corps.
BUT, this is going to be less true within the MARSOC community. These guys know EXACTLY what they want, and why, and they have good reasons for it.
The cadre of that bunch are world class shooters, have been to pretty much every one of the top-line shooting schools like Gunsite, and have probably shot every pistol in existence. They know what they are talking about.
One thing to keep in mind, the requirements for a MARSOC pistol are different than for a standard military sidearm. Everywhere else, a pistol is considered to be a self-defense weapon, and a last ditch one at that. If an officer or Staff NCO has to draw his Beretta and get in the gunfight, things have gone seriously bad.
Not so in the SOC environment. The SOC pistol is considered an OFFENSIVE weapon. On a Direct Action mission, when a shooter's carbine (whatever it is) goes down, he is expected to transition to the pistol and continue the attack just as aggressively, and knock down bad guys just as fast and hard. And if the pistol goes down, he better be ready to bust heads with it.
The 20,000 round count is not a joke. I went through the entire MEU(SOC) shooting workup. The platoon involved was armed with the MEU(SOC) .45s. They didn't have extras laying around so my team had to do the workup and deploy with Berettas. As I posted in the Beretta 92 thread, none of our 4 brand new Berettas made it even halfway through the course before they broke. All of them. And I'm not making that up or remembering wrong.
They shoot the $*%$^ out of those pistols. Actually I'm surprised the round count was that low. If a SOC pistol breaks every 20K rounds, it would basically have to be rebuilt or replaced after every deployment, or maybe two.
The MARSOC guys speak loudly and clearly within the Marine Corps. If they thought a polymer frame wondergun was better, they would have them.