Yup, ICE adopted the P320 as well, specifically in 9mm. The article I read on the DHS site at work stated that there was a "negligible" difference between 9mm and .40 S&W in terms of terminal ballistics with regards to the types of incidents that their agents encounter. Also, the issues of ammo costs and recoil were cited. The agents I work with seem to almost universally despise their current Sig P229 DAK's because the long, heavy DAO trigger is tough for many of them to master, and a lot of them were doing cartwheels when ICE approved the Glock 19 and G43 for duty use (those are not issued pistols, but agents can buy their own and carry them). So far, at least half of the agents I've talked to seem kinda "meh" towards the P320, mostly because they automatically associate the P320 with their current Sigs, even though they're completely different creatures by design; the other half are happy because it's a definite improvement, at least in trigger and ergonomics (and I suppose weight), over the P229, although a couple grumbled about "downgrading" to 9mm because they're still convinced that .40 S&W is the bee's knees.
In the meantime, us lowly contractor scum are stuck with the M&P40, which to be honest isn't bad - as far as .40's go, the recoil is actually pretty mild, and it just plain works - but not many folks I work with have a lot to complain about with that platform, aside from the mushy trigger and the tendency for the slide to release itself when you ram a mag in with authority. (More than a few times, I've racked out a live round by working the slide out of habit after inserting a mag.)
