Good things first:
The service I received in ordering this holster was impeccable. I enquired about getting this done as a custom job before they ever listed covert holsters on their site, and instead of charging me for a custom job, they instead moved up their plans to tool up to make this holster and sold it to me ahead of time at no extra cost. After a delay while they set up tooling, shipment was fast, easy and arrived safe and well-packaged.
Unfortunately, the product itself isn't as good.
As a holster it's perfectly functional; though I prefer a positive click when I holster a gun, that's not actually necessary, and I have no doubt that it will hold my airsoft gun while I move around in potentially extreme ways. However, from the pictures on the rest of the website, it seems pretty clear to me that this is just one of their Pro Series outside-the-waistband (OWB) holsters with soft belt loop attachments and, as far as I can tell, no other modifications made to make it a better inside-the-waistband (IWB) holster. The silhouette of the holster still takes up just as much space, meaning that it fits awkwardly inside clothing, and if I try to wear it in the appendix (AIWB) position, the part of the holster that extends below the barrel of the gun digs into my thigh in a way that a more specialised AIWB holster would not.
In addition, there are no 'concealment features' on this holster, i.e. a wedge to push the barrel away from the body and tuck the back of the frame in or a claw/wing to rotate the bottom of the grip towards the body. When I asked about this before purchase, I was told this was because they improved only concealment and not comfort, which would of course not be much of an issue for an airsoft gun. However, since receiving the holster, I've come to think that these features would significantly improve comfort as well, as they would reduce the space available for the gun to shake around against the body during movement. Besides, I'm of the opinion that even an airsoft AIWB holster should conceal well, simply because the reason I'm choosing AIWB at all is because the costume I want to bring to my games revolves around a 'covert' aesthetic, and having a gun obviously printing through my clothes spoils that somewhat.
In all, I would really like to see Kydex Customs put some more design work into this product, and though I can't fault their customer service, I can't recommend this particular product.