Access and Concealment work against each other. The more access 9or speed of access) you want, the less concealment you must settle for. Conversely the more concealment you want the more you compromise access. And access doesn't mean some IPSC speed draw...it simply means getting the weapon in hand, quickly under duress and possibly while moving.
Concealment is relative. You don't need an undercover operative overseas' concealment for every day life in normal America. I go about my life in AZ with either a Glock 17 or 19 under anything between a simple T-shirt to a polartec hoodie. I have no issues hiding a big pistol like this. Sure it requires some clothing choices, but like I have said for the last twenty years...the gun comes first...the clothing comes second. Do that and you will see what you can carry. Sadly, most people do the opposite and buy the pistol they can hide in their skinny jeans and justin Beaver t-shirt.
That said, there are times when you compromise.
Sometimes the social requirements might preclude large pistol carry but concealment is not quite at the NPE level. This is where the Glock 43 and 42 shine. They have same manual of arms...work the same way and can be carried in the same places...in a holster. I would never advocate pocket carry, or jock strap carry, or any carry of a striker fired weapon without a holster. If you do that, explain to me why and how you guarantee your personal safety because I can't imagine doing that.
Beyond the compromise level discussed, we also have NPE carry. We used the term here at WT about ten years ago and now it is a common term in the industry. NPE carry means this. You are carrying against the strictly enforced rules of the location you are in. They could be actual laws, or perhaps company policy. But you have decided to carry anyway out of a common sense understanding of needs. But you know that if you are discovered, you will either be killed, arrested and imprisoned, or fired. THAT is NPE carry.
NPE carry is done without a holster and there may be a need to discard, or at least temporarily divorce yourself from pistol and magazine. Deep concealment and holsterless carry is the rule of the day. Other than places like NY, Chigaco, or Los Angeles, there are very few true NPEs in the USA. There may be an NPE in a work setting, but that is all. In 99% of peoples lives, they do not really need to do NPE carry, and can opt for a better compromise.
The best NPE pistols? You will laugh but here goes.
Top choice...a J Frame Revolver. Easily carried in waistband, underwear, or anywhere. Trigger eliminated the need for a holster, and no ballistic signature left behind if operating OCONUS. Speed strips or moon clips can be pocket carried and easily discarded as well if necessary.
Second choice...some sort of Double Action semi auto of the size of a Walther PPKS, SIG P290, Seecamp, etc. Again...and this is important...the heavy double action trigger acts as a safety allowing holsterless carry.
There is no third choice.
This Sig 365 is not an NPE weapon. It is a compromise weapon between regular Free American Carry and Non Permissive Environment Carry (Social Compromise Carry??). And that being the case...what does it do that a Glock 43 does not do? Nothing as far as I can see. Is it smaller? Sure but in Social Compromise Carry use size is not as big a factor. Does it have a few more rounds? Yes...that is true but notice that grip and frame girth have been omitted from the chart. You want more gas in the tank, that tank must expand. Make the tank fat enough and the weapon now competes in a different genre.
For the guys that hate Glock (a few people hate me as well) this may be a good choice as it will for those who prefer a SIG 320. Glock 43 killer? Please...let's be serious? The 43 is here to stay and sets the bar for its niche. NPE Carry? Nope...not with a striker fired system. So it is really SIG's entry into the Social Compromise Carry which was heretofore occupied by the very nice SIG P239.
Will I buy one? Not likely.
Will others in the market buy them? Of course they will...but I would suggest they wait to see how it fares with triggers and all that jazz before committing.