I chose not to use iCloud for a variety of reasons.
First and foremost, 5GB is not a great deal of cloud storage – Box.Net for example commonly gives away 50GB storage space. Secondly any application data will not be available on any of your Android devices. Third with many providers giving away massive amounts of storage, it makes little sense to become tied to iCloud, especially for backups. This would almost certainly require the need to purchase more iCloud storage in the future, which is something I have no desire or need to do.
For a better “cloud” storage solution available from virtually every device, see this post on how to get a free Dropbox account that can be used with your iPad, iPhone, Android, Mac, and Windows devices. For even further information on using Dropbox with your iPad or Android tablet, tap the Dropbox link in the tag cloud or use this link.