The "perfect" concealed rig is like finding the perfect girlfriend. I've been carrying concealed now for several decades in one capacity or another.
In Oregon, I carry on the belt because the way Oregon law is written "on the belt" can be viewed legally as either legal open carry or legal concealed carry. That's the way the law is written. As soon as the gun comes off the belt, the rules change and the gun MUST be concealed to be legal.
So, legal issues affect carry choices.
Shoulder rigs are for working detectives and TV police shows. Somehow it needs to be covered. That means a jacket, or if you're CCW with "Thunderwear" -- Spandex shirt with a gun pocket as I understand it -- you're limited in what sort of shirts you can wear.
Cowboys -- from the historical perspective now -- wore vests to conceal their guns. Vests work. I carry a pocket gun in a utility vest.
Sweatshirts work for concealed in the waistband -- IF a sweatshirt is appropriate dress for what you're doing.
Fanny packs scream "GUN!" --
I've carried a gun in a portfolio. But then a portfolio was an appropriate accessory when I was carrying it.
Guns for concealed carry . . . (Puts on Willie Nelson and Placido Domingo singing "All The Girls I've Loved" . . . )
J-Frame snubby, hell of a CCW gun, .357 mag, but it's five shot.
K-Frame snubby, .357 mag. Too big!
K-Frame 4" bbl, .357 mag. Too big, but I've carried one.
NAA Guardian, 32 ACP -- tiny, slips in a pocket. It's 7 shots, and 32 ACP. It's the gun I carry when I'm "not armed."
Kel-Tec P-32 -- Like the Guardian, but it feels like a squirt gun, and I just couldn't warm up to it.
Ultra Compact 1911 -- I don't like "cocked & locked." Single stack, single action. And they're BIG no matter how compact.
Kahr MK9 -- Kahr is making smaller, lighter. 9mm, I like it. Still it's not perfect.
Makarov -- single/double action. I like it but 9mm Mak is only slightly more potent than 380 ACP.
Colt Mustang -- 380 ACP version of the 1911. It's 380 ACP, too small.
Smith & Wesson 629, 4" barrel, 44 magnum. I've carried it. Not easy to conceal. Law says on the belt it need not be concealed.
Springfield XD, Tactical 45 ACP -- 5" bbl. I have a laser sight on this. It stays in the car.
Rem. 870 shotgun, 20" bbl. I can carry it under a trench-coat, but most of the time it stays in the car.
I've bought, sold, traded a lot of CCW guns. I have a large basket full of CCW leather. ALMOST went for the Galco "Jackass" shoulder rig for a 1911.
What works for CCW is to have options. What I carry to Safeway to get a quart of milk is entirely different than what I carry into the wilderness to go fishing.
Law, weather, your activities determine what and how you carry CCW. It's like choosing footwear.