You might want to consider the 22 TCM. It's easier to reload, comes in different sizes and uses the 1911 build and is every bit as fast and lethal as the 5.7. My only advice is to make sure it fires the 40gn. as well as the 39r. The ammo is cheaper and more plentiful too.My "new job windfall" is going to buy my a new gun. I'm kicking around several ideas ranging from a lightweight .308 AR to a 1911 45ACP +P stoked with 450SMC. But the 5.7x28 is quite intriguing to me. I'm too cheap to ever buy a FN FiveseveN but the Ruger 57 was looking interesting, that is until I stumbled across the PSA 5.7 Rock.
So far, literally, every review I've found of it has been positive. Lower price, decent trigger, more capacity (23+1), more affordable mags, optics ready options...
OTOH, it's out of stock all the time and seems like there's only one company making OWB Kydex for it (WeAreNerd). And it's a "full size handgun" that is a tad longer than the G17 in OAL with more of a slide.
And 5.7 ammo ain't free. I like being able to reload to save money on practice ammo and, as @greg_r has noted, 5.7 ammo has a reputation, at best, for being errr... "fiddly."
But the round is flat shooting, claims 30% less recoil than 9mm, has what looks to me to be good terminal performance, is endorsed by people I trust as being very effective for social work, and, in the event that Russia invades, most of the ammo will penetrate NIJ II soft armor and about 1/3 of boutique commercial offerings will penetrate Level IIIA, and that's nothing to sneeze at.
...still, I'm pretty cheap.
Peace favor your sword,
Kirk


I just custom built this one in commander size but you can get a much cheaper version from Rock Island Arms.