A lot depends on where you like the gun to rest on your belt. Some set the gun up high for maximum access but less concealibility, others set the gun lower on the belt for maximum hold and concealability but they are a bit harder to get to. There are also varying cants or the angle at which the holster holds the gun. Most appendix carriers prefer zero cant (straight up and down), while those who carry at 3:00 or past prefer some cant.
I prefer the holsters that hold the gun lower although I have both types. I am always climbing in and out of trucks and tractors and bumping in to stuff, so I like the extra hold offered buy the lower position. If I am just running to town I might switch out holsters and go with the higher position.
Note in the photo belo the holster on the left (Side Guard Quick Clip) holds the gun much lower than the holster on the right (Don Hume H-715). Look at the sideplate screws of the two guns, not the grips since those are different angles.
The holster on the left also has 30 degrees forward cant, whereas the Hume has zero cant. Both are excellent choices but if I had to pick just one it would be the Side Guard (but they take about 12 weeks to get).