well, a cfw for 5.05 would be absoulutely pointless, i think it was only needed for one game and wasnt released as a proper downloadable firmware, just on the UMD. To play that UMD on cfw, you can just use 5.00m33-6 with version.txt from 5.05. however if you meant 5.50, then as stated above it has not yet been decrypted and there are no plans for a cfw based on it. but the main new feature is subfolders which i think are possible through a plugin, or at least could be if someone bothered to make one. other than that there are a couple of bugs in the new firmware as it was rushed out to patch .tiff exploit which was released just days before hand.