I haven't used this specific brand of holster, but I do have similar holsters in one of my huge tubs of holsters, and, in the interest of full disclosure, I am an NRA and Utah certified instructor, which does NOT by any means make me the ultimate holster expert.
So with that out of the way, the holsters on their web site all appear to be soft nylon holsters with retention straps. On the plus side, these holsters are inexpensive and can be used with a wide variety of handguns. This is because they're soft and flexible and thus often hold guns they weren't even specifically designed for.
The generic problem I've had with soft nylon holsters is that they ARE soft and flexible and don't hold the gun securely in the holster. A retention strap is required to hold the gun in the holster. Guns often move around while they're in the holster, again, because the holster is soft and flexible. Photos on their web site of the narrow, single belt loop, or metal clip, suggests strongly that the holster will have a tendency to flop around on your belt and isn't held securely to your belt (the holster easily slides along the belt). All of this creates a situation where, when you reach for the gun, the holster isn't held in a secure and predictable location on your belt, AND the grip of the gun in the holster can move around, making it more difficult to get a firm grip when you need the gun for self defense. The video on the readyholster.com website shows EXACTLY this kind of flopping around as the gun is being drawn.
Further, those retention straps could be problematic when re-holstering as the flexible strap could enter the trigger guard and pull the trigger as you're re-holstering. Oops!
You didn't mention the type of holster you're considering. If you're thinking of an inside the waistband type, consider that a soft nylon holster will collapse from the tension of your belt. In order to holster, or re-holster, you going to have to put your fingers in front of, or awfully darn close to, the muzzle of your loaded firearm in order to open the holster mouth and get the gun into the holster.
A good kydex (plastic) holster isn't going to be much more expensive than a soft nylon holster (perhaps $50). A quality leather holster will be more expensive ($100 more or less). Either will give you a platform where the gun stays in place on your belt and the firearm is firmly held, so when you reach for it, the grip will be right there where it always was when you practiced your draw and presentation (and by all means practice frequently). So, bottom line, in my opinion, there are other holster options that will serve you better.
I hope this is helpful.