I would like a discussion on this topic... Here's my take.
General (pure) qi cultivation techniques move the qi from the dan tian around pressure points and meridians and then augment it with the air from outside (QZ and AT qi).
Then there is advanced (purest) qi cultivation, which is about the same but is not confined to the pressure points and meridians (i.e. YJJ, BMZC).
Then there is abundant unrefined qi, which although grows to a greater amount in a shorter time, is unrefined, hard to control and resulting it in being of less quality (i.e. HQG & YG's physical training qi)
Qi can then be used in 3 ways, overbearing, precise and powerful, refined and pure.
Overbearing would be something like YG's Sad Palms and maybe Hama Gong, which overwhelms the enemy with brute force.
Precise and powerful is something like XL18P which effectively uses the qi as a force for attacking.
Then there is the pure and refined type of using, which uses qi extremely effectively for whatever reasons, such as YiDeng's YYZ.
As a side note, i believe that YG's overbearing distribution type of internal energy is not as helpful in curing injury (he went to catch the fox instead of curing the Shi ghost). And it gets better, the more precise and refined it is, i.e. GJ's precise and powerful distribution of qi is not as effective in controlling internal injury as YD's pure YYZ.