None of us is going to be able to help you make a choice
. Folks like what they like, don't like what they don't, and have a list of reasons to rationalize both. But who can argue with what folks like?
Be aware, that the actual difference between the two that can affect a decision, is breathability of the materials. Leather will allow moisture to pass in both directions, through the holster walls, such as humidity condensing on the pistol or sweat trying to enter the holster. This allows a certain equilibrium.
Kydex sheet, unlike say sheet nylon (not the fabric; the solid), is not hygroscopic so doesn't absorb or give up water. In that case, 'good' that it won't absorb sweat, 'bad' that it won't breathe condensation.
The usual gripes about Kydex are noise and wear on the pistol; even on the polymer frames. Leather is quiet but of course can still wear; in both cases choose something that fits closely. Kydex is an amorphous plastic (so softens with every degree of temperature rise; it is how they are molded) so don't like being left in hot cars.
Fabrics are quiet and breathable but water resistant; their weakness is a lack of structure. A holster is more than a carrying pouch: it's a launch platform that also is a helipad; presents and releases the pistol readily, always on stand-by to receive the pistol readily. And it is here that fabric holsters can come up short; an exception is the range that Elite Tactical sells that uses exoskeletons to provide structure (positioning, carry angle, passive and active tension/retention, etc.).
Did you know that Safariland is in the process of dumping Kydex? They popularized it along with Bill Rogers but are switching over to injection molding; which is what Rogers is actually best known for: he's a plastics man not a holster man. The shift has been announced in the Florida press. Why would they do this? Because Kydex has always had substantial weaknesses that crystalline polymers like nylon don't have (for example); eliminates their made-in-Mexico operations and they can stop so-marking their products; and most importantly, raises the 'barriers to entry' for competitors; something they've always relied on their patents to provide. Oh, and cheaper!
