Switching from Rom to Rom

[aceofspades923]

I have seen a lot of people on here talking about checking out all of these rom's. I just downloaded Juicy 6, and want to move to Juicy 7 or maybe try out Mighty. I was wondering do you guys backup immediately before you switch to another rom? Wouldn't that mess up some things when restoring a backup from an old rom to a new rom?

Unrelated: if anyone knows why I can't connect to activesync after downloading juicy 6 (which means i can't go to another rom), please let me know.