I don't even know what I would store in the cloud. I use Time Machine to backup to a Time Capsule, and I sync my iphone and iPad to my Mac. iPhoto library is on the Time Capsule. Maybe I'm doing it wrong, but I guess I don't really have any need to keep all my stuff in the cloud, except for music, but that's part of iTunes Match.
iOS 8 allows you to save your photos in the cloud and just leave thumbnails on your phone, so it frees up a ton of space. That's primarily why I'm switching. I use OneDrive now, but the iCloud Drive will be more seamless.
Also, with iCloud Drive, a lot of your apps will be storing data there automatically.