I've looked into 6.38 ME v3 and 6.39 ME-9.1 and on both the CFWs, the Readmes say "The degree of stability is still unknown. Please test it on your own and refer to different people's test reports."

Is there a good, stable CFW?

I have a fat PSP 1000 on 5.50 CFW and I'm looking to upgrade.

Auto-Merge: Also, I have a question.

It says:

1. copy UPDATE folder at ms0:/PSP/GAME/.
2. Put 6.39 official update at ms0:/PSP/GAME/UPDATE/639.PBP .

I see the UPDATE folder.
I don't see the 6.39 official update.

I'm a bit confused.