texblend or visible for multiple textures

[vizmaster]

I have implemented the flipping between textures two different ways and would like to know if there are advantages to either approach (memory management, limits, etc).
I am loading about 1GB of texture at a time. Therefore, I would like to be displaying one texture while loading the next.
First approach was to have tiles that have two textures each. Then use texblend to flip between them. I used director to load a new texture while displaying the other. The only drawback I have seen is panning over the texture was slowed by the loading. This was not visible when I moved to a faster PC.

Second approach was to load each texture onto its own set of tiles. Then switch between them with quad.visible(viz.TOGGLE). This works well in that I can pan the texture while loading the other. However, as I try to load another texture I run out of memory. Removing the old textures at the right time may resolve this problem.

As I initial said I would like to know if either approach is better and for what reasons. Thanks,