I only have two makes/models of IWB holsters. One is leather like you're asking about and the other is Kydex. I like and recommend both.
My first IWB holsters are leather Milt Sparks Summer Special II's. Excellent holsters. Most other good holster makers make copies of them.
My latest IWB holsters are Vedder LightTuck Kydex holsters. Also excellent holsters. So far I don't know of anyone else making a version of this one.
I find both holsters to be comfortable.
The Sparks are a bit pricey(>$100) and take a while to receive once ordered.
The Vedder is only a week or two lead time to your door and well less than $100. I bought my first Vedder to have a holster while waiting on a Sparks to arrive. I liked it so much I never ordered the Sparks.