Documents & Data - iCloud question

Hello all!

I would like to remove my jailbreak from my iPhone 4 (reason being that the novelty has worn off amongst few other reasons). However, i'd like to keep all my Angry Birds data that i have spent ages doing since jailbreaking. If i was to restore as new then i'd obviously lose all of it, and if i was to restore from a backup while jailbroken then my 'other' memory space won't be restored to the normal levels. I do have a back up from before i jailbroke, but i'd prefer not to use it as it means i'd have to complete even more angry birds!

If i was to sync all the app data to iCloud, then restore as new through iTunes; and then turn iCloud 'documents & data' on through my newly restored phone; would i have all my angry birds saves?

I don't think i fully understand iCloud still!

Thanks

Edit: Think i may have posted this in the wrong section, if it should go in 'iPhone hacks', could someone move it for me.