I've only seen one review on the Tagua shoulder holsters. I came across it when I was googling them, as I was impressed by the price.
Anyway, the person who reviewed them was a dealer. He said the the stitching was, sometimes, inconsistent, but the holsters were very high quality for the price. I can't find the review anymore, though.
My wife and I had a few Tagua belt slide holsters. They hug REALY tight and they're REALLY stiff. The draw is not as fast as other leather holsters due to how freaking stiff the leather is. The leather gets torn up if there are sharp edges on the gun, such as a loaded chamber indicator that pops up, an external extractor, slide serrations, etc.
My wife had a Tagua belt slide for her Glock. The external extractor rubbed bits of leather off onto, and sometimes into, the chamber of the barrel. That worried us as we didn't want any bits of leather getting chamber or the rest into gun.
My Sig P220s slide serrations ate up my Tagua belt slide, as well. It scraped the leather off into tiny bits, which got all over the outside of the chamber on the barrel.
We both quite using leather and went to Kydex/plastic holsters, as they seem to proved a much quicker and smoother draw. High speed/low drag.