Larry, other than minor difference they're basically the same. Depends if you want one with a safety or without. They also have ones with red dots pre-installed. Personally I carry the sig p365 xl and love it. I found the standard 365 the grip was to small to get a good grip and went with the xl Wich is just slightly bigger and fits my hands perfectly while still being small enough to comfortably carry. If interested here's a link to the one I carry, I chose one with a manual safety but sig also makes them without. Hope this helps, link here................. budsgunshop.com/product_info.php/products_id/151819/sig+sauer+p365xl+9mm+3.7+x-ray+sights+new+optic+plate+12+1+manual+safety

just get the one that has the features you want. For Me I want a manual safety on a carry gun. I dont like red dots so those would drive me in selecting which one I want

Larry, the core 365's are really the same in function. It would boil down to size and caliber that is best suited for your carry needs. I highly recommend taking a trip to a local brick and mortar to handle firsthand to see which fits you best. Cheers and stay safe!