Coldbird posted this in another thread:
6.20 version: useful if you have a 1g, 2g, 3g, 4g or 5g unit... because you can install our permanent bootloader.
6.35 version: obsolete, but still supported... i suggest moving to the 6.39 version however.
6.39 version: best for 1g and 2g units because you can use the bundled cipl installer to make it permanent. 6.35 and 6.39 are the only way for (temporary) cfw on 7g and 9g units at the moment, cause 6.20 version lacks 7g and 9g driver modules.
Summing up... if you have a 2g (unhackable mainboard) to 5g unit... move down to 6.20 and make it permanent via our bootloader installer.
If you have a 1g or 2g (hackable mainboard) unit, move to 6.39 and make it permanent via our cipl installer.
If you have a 7g or 9g unit - use 6.39.