I own a Bersa Thunder 380 (not the CC model) and occasionally pocket carry it in a sueded leather Galco Pocket Protector holster. It does fit in the front pocket of pleated Dockers or blue jeans. However, it's relatively heavy as a pocket gun and I prefer to carry a S&W 642 .38 revolver in a Desantis Nemesis holster if I am going to pocket carry.
With the optional 9-round magazine that gives you 10 rounds of .380, which is a decent amount of rounds to put downrange if the situation called for it. However, that extra magazine length puts it out of the pocket size for me, so I only use that for belt carry.
It is arguable whether 10 rounds of .380 from a 3.75" barrel is superior to 5 rounds of .38spl +P out of 1 7/8" barrel, but there are always tradeoffs when looking for concealment.
The Bersa 380 is very comfortable carried at the 3 o'clock position in a quality IWB holster (I use the Striker model from www.ubgholsters.com
). However, that does require an untucked shirt, and like you, I prefer to tuck in my shirts.
I have tried a tuckable IWB holster before (for a different pistol) and found that unless you have very short shirttails you get a big bunching up of cloth around the gun, and it seemed that it would take a bit of tugging to untuck it and get to your gun in a hurry.
While I like the Bersa 380 and enjoy shooting it, I agree with many of the other posters here and would have to say that for the same general size and weight you can find some very good single stack 9mms.
At the time I was shopping for an affordable semi-auto for concealment, there weren't many choices in 9mm and I was not as educated on the relative effectiveness of handgun ammo as I am now. If I were in the market today, I'd skip the .380s and be shopping for a pocketable 9mm.