I am saying I would like to be able to actually edit and modify my image data on the CPU side, my big thing is authoring and having compression and decompression codepaths.
not to mention they each seem recommended for different common usecases, meaning I would probably want I think it was to support the main 3. Which pretty much made me threw my fist up.
So I'd highly recommend pushing readonly textures to GPU in BC/S3TC (same thing, two names) simply because memory is so slow and processors, especially GPU, are so fast.