There are dozens of comfortable ways to carry a gun. Carrying the the 9000 IWB, can be a little challenging due to the width but where there's a will there's a way.
For IWB, I normally carry about about 3:30-4:00, so just behind the hip.
If it's not comfortable, there could be some easy fixes.
For the Desantis/9000 combo, are your pants about a size bigger than you would normally wear? For IWB, if your pants were tight in the first place, adding a few inches in holster and gun can be pretty uncomfortable.
A stiff, thicker gun belt will help to support the holster and distribute the weight better.
Really, everybody is different and what is comfortable to some is unbearable to others. For where you wear it, it really is a personal preference. Just try moving it around on your belt until you find a place where you can draw from it and where it's not digging in anywhere. And after you wear it for a few days, it will begin to mold around your body shape.
Leather takes a while to break in(and sometimes so does your hip

).
If you find that you just can't get comfortable with the Desantis, there are hundreds of other options. Most of us have a box full of holsters that just didn't quite work for us. Just don't settle for the feeling that you will always be uncomfortable. If you are uncomfortable, that just means you have more shopping to do or something to look forward to from Santa

.
Currently, the Brommelland Max Con V gets the most wear time from my box of holsters. Some holsters will just work for you better than others.