I have no issues retrieving my weapon from my back. I am right handed and got the left hand IWB holster so that when worn, I reach back with my right hand and get quick grip on weapon. A lot will depend on clothing etc.
Are you looking for IWB? I bought a Kydex Tulster holster that I carry IWB in the middle of my back. I barely feel it when worn and it also has an adjustment screw to adjust the tension on the weapon.