With ccz compression you can encrypt your sprites sheets so no-one can easily rip them off.
Also make sure you select PVRTC2 or PVRTC4 for image format for the pvr file. You will get x16 or x8 less RAM used compared to PNG 8888.
The compressed pvr files will also render faster due to lower memory bandwidth and better texture cache usage.
Beware though, TexturePacker doesn’t yet allow you to create mipmaps. You’ll need to use PVRTexTool for that.