LUngha, great post.
When acne scarring involves fat loss, the actual indentations can actually overlap with sunken areas of the cheeks due to repeated inflammation and destruction of the fat layer. This was my problem. Not only did I have indentations, I also had fat loss because my cystic acne keep returning in the same spots. As you can imagine, after being damaged repeatedly the whole area looks like it lost volume.
Personally I feel Radiesse is a bit outdated, since Voluma can be injected deeply to add fullness and volume back to the cheek area. A thinner filler like regular Juvederm or Belotero can be used to fill the actual indentations themselves. Radiesse sets very hard, and very prone to lumps and bumps if injected superficially in the skin. It is always nearly injected below the skin, in the subcutaneous fat, to prop up a sagging face. Think of it more like an injectable implant, than an actual filler.