This is the info I used when deciding to go ahead and get one.
https://sigtalk.com/p250-p320-p320-x.../topics/328040
February 12, 2018 Sig stopped production to address some quality control issues. On February 15, Sig said there would be a new option of Xray3 sights instead of Siglite sights and the new option resulted in a new SKU: 365-9-BXR3 vs 365-9-BSS (presumably for P365, 9mm, Black nitride finish, X-Ray 3 vs Sig Siglite sights).
On February 19 Phil Strader announced that they were resuming shipments and that all new P365s would have the Xray3 night sights along with revised recoil springs. They also started making some extra relief cuts to address cosmetic barrel peening issues. Most people call this the start of Gen2.
June 10 and later Gen 3 -- these guns have the redesigned striker.
the link will give you more information on serial numbers, but I'd look at a serial number after 66A100000 and dated after September 1 to be well into the ones with the most current modifications.
Finally got to run my 365 at the range today.
Build date is Feb 19, 2019 and it's the X-Ray version.
300 rounds, 5 different brands, all 124gr. My carry round is Speer Gold Dot LE 124gr +P and it ate 50 of those. No malfunctions or hiccups so far.
Impressions:
I still can't believe it holds 10.
Grip texture is excellent. I have large hands so even with the small extension of the standard magazine I'm not getting my pinky on.
Handles well and is controllable.
Punishes a bit with full house +P loads, harder than I thought it would. Definitely less comfortable than my Kahr PM9 with the same rounds.
Impressive accuracy for such a short barrel and sight radius, but nothing earth shattering.
Like many of the micro 9's the ejection pattern is a bit random, but nothing back at my face.
Mags don't fall free, which is annoying, but that may change over time.
Trigger is excellent for a gun this size.
I'm liking this gun a lot so far.
I want to rent one with extended mag, I have only held them, drip is up there as near the best texture for poly. There are some very slippery old glocks, early Xds, and even the more aggressive XD grips is just a deep channel, not real micro grip like this sig.
I'm impressed with the way it handles. Ill continue to wait it out, but I think its getting refined enough for me to buy.
Kinda waiting for smith and wesson, SA, maybe CZ or FN and maybe someone else to copy the packaging and come out with there version that is basically the same configuration.