I decided to give AlienGear a try for my SW99. The clips are incredibly stiff as mentioned above, but that is nore something to get used to than a complaint. It is just as comfortable as other hybrids of its type, though the Kingtuk has smoother leather backing which is more comfortable on bare skin, though not by a lot. The thickness of plastic and leather are a non-issue, as mentioned above.
My complaint on the holster is that the leather backer that they claim is cut for a full grip on the gun does not necessarily allow a full grio. For my SW99, where the web of my hand meets the gun is partially blocked by the leather. I can still draw, but it shifts my grip slightly and introduces some discomfort.
the leather can be trimmed, supposedly, but I haven't decided if I want to go that route or buy a different holster. I have another similar styled holster for a different pistol which doesn't have that problem, so I might just source one of those and send back the AG.
Quality is great on Alien Gear, just doesn't quite fit my needs out of the box.