iCloud offers limited storage.If you're using iCloud for mail, calendar and mobile device backups, you'll probably fill up that free 5GB limit pretty quickly. You can buy more space, which is easy to do and reasonably priced, but that seems like a poor move when Google offers 7GB for just your webmail storage.
iCloud's web interface might be blocked.Since iCloud is considered backup storage, it's likely to be blocked at more strictly secured work or school computers. If you need to check your calendar from your work PC, you're out of luck. We've already (dissapointingly) experienced this first-hand. Google Calendar, however, loads up just fine and even syncs with Microsoft Outlook with Google Sync.
iCloud won't sync with your non-Apple devices.Prefer reading on your e-ink Kindle? Do you check email and surf the web from a Nook Color (like me!) or another Android tablet? Well you can't use iCloud there. Your best bet, if you're set on iCloud, is to buy up an iPad 2, which increases iCloud's startup cost from free to around $800.
iCloud only backs up Mac-made documents.iCloud will automagically backup any important docs you're working on in Pages, Keynote or Numbers, so your days of worrying about failed hard drives are over. Unless, of course, you opt to use Microsoft Office, Open Office or some other non-Apple document creator. Then you're out of luck.
iCloud requires the latest operating systems.If you want to use the full features of iCloud, you'll need to update your iPhone, Ipod Touch and iPad to Apple's new iOS 5 operating system. The good news is it's free. The bad news is if you don't have one of the three latest iPhone releases (iPhone 3GS, iPhone 4 or iPhone 4S), you can't get it. And to access iCloud through your Mac's apps, you'll need to have Mac OSX Lion 10.7, which comes at a modest price tag of $29.99. Did we mention Google Sync is free?