I just spent half an hour going through each file in the OTA upgrade ZIP and comparing its CRC (checksum) to the same exact file in the "leak v3" PB00IMG.ZIP, including all of the files inside system.img.
Process:
First off, just by opening the two ZIP files with 7-Zip I can see that the boot.img, radio.img, and recovery.img are identical. In both ZIPs, their CRCs are EA7388FA, 54C41EEC, and 3F0153F1 respectively.
Since the OTA breaks down system.img into just the files that need updating (for the purpose of keeping the file size as low as possible), the only way to compare the files with system.img in "leak v3" was to use the root ROM created from "leak v3". (Thank goodness there's an unadulterated ROM of it, so the original CRCs are intact!) One by one, I compared the CRCs of the files in the OTA's system folder with the same files in the "leak v3" system folder.
Findings:
The files that are in the OTA are completely identical to the ones in the leak v3 system.img, with only one exception: The OTA contains an additional app called UpgradeSetup.apk. Obviously, it's only necessary for executing the upgrade.
The OTA also does not include userdata.img or the PRL file because you're not doing a full wipe. You retain your existing user data and PRL, or you can do *228 x2 to get the latest PRL for your network. (You can also do a factory reset to remove both your user data and PRL.) The OTA also doesn't contain an updated version of HBOOT, which I would argue is the biggest difference. More on that in this thread.
Visual:
To make it easier to compare the CRCs in these images (besides the app folder), I removed all of the files from the "leak v3" ROM that were left unchanged in the OTA. After doing that, the folder CRCs matched, with the exception of the "app" folder since the OTA has that one additional file.
Images below. Hit "show" to view.
Process:
First off, just by opening the two ZIP files with 7-Zip I can see that the boot.img, radio.img, and recovery.img are identical. In both ZIPs, their CRCs are EA7388FA, 54C41EEC, and 3F0153F1 respectively.
Since the OTA breaks down system.img into just the files that need updating (for the purpose of keeping the file size as low as possible), the only way to compare the files with system.img in "leak v3" was to use the root ROM created from "leak v3". (Thank goodness there's an unadulterated ROM of it, so the original CRCs are intact!) One by one, I compared the CRCs of the files in the OTA's system folder with the same files in the "leak v3" system folder.
Findings:
The files that are in the OTA are completely identical to the ones in the leak v3 system.img, with only one exception: The OTA contains an additional app called UpgradeSetup.apk. Obviously, it's only necessary for executing the upgrade.
The OTA also does not include userdata.img or the PRL file because you're not doing a full wipe. You retain your existing user data and PRL, or you can do *228 x2 to get the latest PRL for your network. (You can also do a factory reset to remove both your user data and PRL.) The OTA also doesn't contain an updated version of HBOOT, which I would argue is the biggest difference. More on that in this thread.
Visual:
To make it easier to compare the CRCs in these images (besides the app folder), I removed all of the files from the "leak v3" ROM that were left unchanged in the OTA. After doing that, the folder CRCs matched, with the exception of the "app" folder since the OTA has that one additional file.
Images below. Hit "show" to view.
