There are many aspects to choosing the right holster for you, and only you can make that decision. It's not uncommon to purchase and test out several holster types and styles. Ultimately the holster you will wear every day will come down to; 1) Comfort, 2) Aesthetics, 3) Functionality as the main points of decision.
In general, folks that have a bit extra padding and have no trouble hiding a donut or six, will find that leather is a forgiving and comfortable option. The leather will mold not only to the pistol, but to your curves as where kydex will leave you with soars, scrapes and cuts. Trust me, I know! This is especially true for Inside The Waistband (IWB) carry. It's not as prevalent with Outside The Waistband (OWB) carry, but it can be a factor if you don't have a tucked in shirt and wear your shirt over your carry. Any time it rubs against your skin, you will know it.
A few words on Carry Position
Carry position is also a huge factor when deciding what type of holster you wish to carry. Smaller waisted folks tend to like carrying apex (the 1 o'clock or 11 o'clock position) or right in the front (12 o'clock position). Anyone with a bit of a spare tire, this is not a good option as it will poke and jab your guts to no end. You will hate life carrying, trust me.
Back carry is another option, but the comfort of this location depends greatly on your vocation. If you're driving a lot or sitting in an office for long periods of time, this may not be your optimal carry location. If you're in a trade where you're on your feet a lot and not sitting, it's a great option. This carry position ranges from the 5 o'clock to the 7 o'clock position. Another thing to consider when carrying in this location is which way the pistol grip is set. Is it up or down? I recommend that you figure out how your hand most naturally and comfortably seeks to find the pistol grip. Is it palm in or out?
Finally, the most common position that folks tend to carry is their hips. This is the 2 to 4 o'clock position for the Right Hand Carry (RHC) or from 8 to 10 o'clock position for the Left Hand Carry (LHC). This position is most common because it allows for easy access to the firearm and offers a more natural draw.
Shameless Plug:
Regarding how you most comfortably carry your firearm, this is where Legion Leather sets themselves apart. We don't just build a leather holster to fit the pistol, we tailor the holster to you. What that means, is that we look at how you will most naturally draw your pistol. From the ride height on your belt, the cant angle (forward or back), the position on your person and holster style to fit your carry preference. We tailor the holster to put your pistol grip right where your hand expects to find it when you reflexively go to draw.