One of the newest guns out this year is the Springfield Armory XD-S 9 mm with the 4-inch barrel. Tasked with reviewing this firearm, I started looking around to see what was available for holsters. I came up pretty empty until I hit the CrossBreed website. Not only does the company have OWB holsters available for the XD-S 9 mm (CrossBreed makes open holsters, so the extra .7 inch of barrel and slide doesn't matter), it has its signature SuperTuck Deluxe available.
A fine marriage of leather and Kydex, the SuperTuck provides a stable platform to carry even large-framed firearms discreetly. As the name foretells, this holster is "tuckable", meaning it can have a shirt tucked in over it, hiding everything except the belt loops under the cover garment. It's a trade-off where you lose a little bit of accessibility, but if you need absolute concealment, there's not much better.
Having been the proud owner of a CrossBreed holster for many years now (the model I have—for the Walther P99—is so old, the company hadn't started stamping the cross directly on the clips yet), I can attest to the comfort and concealability of this holster with even a large handgun. The Smith & Wesson M&P45 full-size also fits this holster, and it's rare to find a method of carrying a 10+1 .45 ACP full-sized handgun under just a button-down shirt.
CrossBreed SuperTuck Deluxe: When you need to carry a large handgun hidden well, this is an excellent choice. MSRP: $69.75.