There are 20M iCloud and 25M iOS 5 users

Apple's rocky iCloud and iOS 5 launches haven't deterred determined upgraders. Today Apple revealed that over the first five days 20 million people had signed up for iCloud and 25 million upgraded to iOS 5. Considering that Apple claims a market of 250 million iOS devices, the numbers are either good or not depending on your view of 10 percent (or less) adoption. It's a fair guess the numbers could have been higher if not for the complexity of this upgrade or data center problems that delayed or thwarted many would-be updaters.

iCloud, Apple's data center-powered synchronization service demands, much during setup. To fully utilize the service, Mac users have to upgrade to iOS 5, iTunes 10.5 and Mac OS X 10.7.2. MobileMe subscribers also must migrate to iCloud, but only after getting the other upgrades. Many Betanews readers report difficulty getting all the updates and iCloud rightly working, particularly with desktop mail clients.

Christopher Sacra explains some of his problems:

I updated my 5 devices with several bumps along the way (took lots of retries). My biggest heartburn is iCloud. I migrated my Mobile Me account, but then, when you are installing the iCloud account on the devices, it's not clear whether to use Apple ID or Mobile Me login, as both can be used on the website. My devices could not retrieve [me.com] email, saying the username and/or password were incorrect. My MacBook Pro told my I couldn't sync because I wasn't using my "Primary iCloud account." Primary iCloud account? Come one - there should be one account to set up and sync. I shouldn't have to decide where Apple wants my iTunes Apple ID and my Mobile Me/iCloud login - can it be any more complicated?

lvthunder observes there is a "lack of documentation. Apple is great at the marketing, but I don't know what all the options are".

Some users also report changes (which I haven't confirmed firsthand). Apple Address Book in Mac OS X 10.6 lets users sync to MobileMe and Google or Yahoo. "If I want to synchronize my address book to iCloud, I need to turn off Google Contacts sync", José Tierno writes. "[It] will not let me sync to both. That just will not work for me. Bummer".

By contrast, Gé Weijers: "Upgrading was pretty uneventful for me. Getting rid of iTunes for backups and security updates is the best feature. The rest is not that important to me".

Many people found iOS 5 challenging, too. For example: "The installation process was difficult, with several failed attempts before IOS 5 installed on both my iPhone and iPad, but now I'm up and running" Charles Bond writes. "But I'm puzzled and can't find an answer to the question: When does a device sync to iCloud -- and then vice versa. It's clearly not in real time, or even close to it. Right at this moment I have an entry to my Calendar that has not been synched to my my iPhone in over an hour, although the phone is on, locked and connected to power via a USB connection to my MacBook Pro. So am I missing something, which might well be the case? When does the magic happen?"

I don't know Bond's setup, but isn't the point that iCloud syncs cable-free?