Well, I avoided the iCloud and upgrading to Lion and iOS5 before the move. I’m getting old: I could only deal with so much change at a time and feared if something went wrong with the upgrade process I could be out a phone and/or computer, which would never do.
Today I bit the bullet and have been migrating everything to iCloud: all of my music, some of my main documents, my iPhone photos (not my 40,000+ Lightroom photos), my address book, calendars, etc., etc.
While the process of checking and uploading has been rather time intensive, things as a whole seem to be working well. My only known issue at this point has been the Lion upgrade on my Mac Pro. Safari is just a mess.
As time goes by, I’ll hopefully become comfortable with the new iCloud workflow.