You'll get a lot of personal preference but I always say shoot and carry what caliber you are comfortable with. I like several calibers and put both .45 and 9 both at the top. As a big 1911 fan, the 1911 in .45 always will probably be tops though. Haven't tried to CC most of my 1911s other than my Springfield ERO .45 cal which is my EDC. When I change up, I go to my Sig 229 which is about the same size. They are a bit bigger and heavier for CC IMO but if it works, it works. If I deviate from that (especially in the warmer months), I will just throw my Sig 238 in my cargo shorts pocket and go. It's so lite you I tend to forget I have it on me. I just make sure I am proficient with whatever I intend to CC.
I'm looking around for another micro carry though and going to give the wife the 238. I haven't found many out there I really like. Not big on Glock. Nothing wrong with them, just not comfortable to or for me. Even though I am a Sig fan, I don't like the spongy stock trigger of the 365. I am also a fan of Walther (my PPQ Q5 match is favorite striker of my bunch and most accurate as well) but Walther don't make a micro. Now looking at the Canik Mete MC9 reviews. I'd like to see one but they sure are hard to find local.