In 3.5, the Settings--->Atlases pane reports wrong numbers for how much RAM is required for scenes, atlases and individual resources. For example, I have a resource that requires about 60 MB of memory and 3.5 reports it to only require 12.3 MB of memory. It seems to consistently under-report all assets memory requirements.
Note: I am sure that I am comparing RAM to RAM and not file size on disk to RAM.
Note: I am sure that I am comparing RAM to RAM and not file size on disk to RAM.