Holsters seem to be as equally a personal choice as the selection of the firearm itself, maybe even more so. Most of us end up with several carry guns and a box full of holsters, some we like and use frequently, and some that seemed like the right choice at the time until we actually used it, and then found it to be wanting in some important aspect or another.
I'll just list a few things that I've learned the hard way and hope that it helps.
For OWB carry - I agree, those systems that sit higher and closer to the body tend to be more comfortable for daily wear.
Snap retention systems are very secure but require regular practice to get the gun out quickly and safely. Those systems that depend upon screws for retention should be checked regularly to be sure there is enough tension. Over time and with use every material leather, kydex or ballistic nylon, all will stretch.
Kydex is great for retention but can be noisy, and can be less comfortable than leather depending on the size of the firearm as it is somewhat less flexible. Paddle Holsters that ride high in leather are good choices particularly for revolvers but size and shape matter greatly.
Buy a gun belt. A gun belt will be less prone to stretching and won't fold over, like a standard belt often does when carrying. Some are made from man-made materials that won't stretch at all. This means less pulling up of your pants.
Spending more money on a rig doesn't necessarily mean that it will work better but the cheapest stuff often doesn't hold up well even from name-brand makers.
If you are a left-handed shooter as I am - Your choices in holsters that fit your gun will be more limited.