I imagine(I've seen the video's)this is very "handy" in the end is it not the same as swapping constantly, on one hand you swap a bunch of 512pow2 textures and the other swaps out chunks in 512pows chunks....am I wrong?
The way I understood it, is it was for the artists convenience at level editing time....for the most part.

Do not get me wrong....I want I want.