If you use a USB Loader to rip the game, it will be compressed (scrubbed). But when you take it to your computer and use WBFS Manager to move it to your computer from the USB stick (or HDD), it will then be uncompressed (4.37 GB). There is another WBFS app called ncWBFStool v1.0 that will let you transfer the ISO onto your computer and the ISO will stay compressed, check the link.
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If you want to burn the ISO, transfer it to your computer with WBFS Manager 3.0. Then use IMGburn (install it if you don't have it) to burn the ISO. All you have to do, once IMGburn is installed is, right click on the ISO and select "burn with IMGburn", that will launch IMGburn. If your new at this, don't worry if the ISO looks like a rar folder, and don't try to unzip it because it will not unzip.
EDIT - also, some USB Loaders have the option to remove the disc update while ripping the image to HDD, you may want to see if your loader is able to do this.