Correct - iCloud backups - as i see it - are mainly for those people who do not have a "central library and computer" that hosts their content. Or if you want to feel more secure in your backup being in Apples world and not on your hard-drive. I do use iCloud backup for the latter reason and have my and my fiance's iPhone 4S as well as my iPad 2 backing up to it.
I've been backing up to both as well but I have an iPad and an iPhone both backing up under my account and just yesterday my iCloud backup failed because I am now over the free 5 Gb. I guess I can just stick with the computer backup.
Let me ask you this are you using a Mac or pc. If your using a Mac just make sure your using time machine to back up your Mac, I would hate for you to lose all your info and not be able to restore your phone cause you lost all your files. Pc is the same just make sure you back up your pc if you are not using iCloud.