The secret service uses P229's in 357 SIG. If any group of people could probably get any gun in any caliber if they thought it held some advantage over current equipment it would be these guys. I am guessing primarily because of the penetration but I could also see other advantages like in longer distance shooting.
My next door neighbor is a retired Secret Service Agent having guarded several presidents going back to the revolver days.
He said they did do plenty of homework when they switched to the Sig. Price played no role, it was all about a rounds ability to stop a threat as instantly as possible with a pistol everyone could shoot well and carry comfortably.