One of the most attractive features of the cloud is accessibility. Can you access your data via iPhone? via Android?
As smartphones, tablets and laptops offer mobile computing options, you want to be sure your cloud storage service offers the same mobility. If you access your files through your phone, be sure your storage has an app for that. This will allow you to reach the important documents, pictures and videos you need when you need them and where you need them.
Sharing / Collaboration:
The second most attractive features of the cloud is ability to share and collaborate. Investigate features for sharing and collaboration. Are they easy to use? Can you easily share a file?
Having cloud storage is only useful if you can access it when you need to. Not all servers are created equal and some companies offer more up-time than others. Usually a storage provider will offer their percentage of up-time if you ask. Choose the service with the most uptime and you won’t be left waiting to access your storage.
Since your files are managed by the other company - their support is very important. If you cannot access your files, it very important that cloud storage provider have responsive and knowledgeable support.
Quality and efficiency of client software:
One of the most important feature is how efficent the client piece of the cloud offering is. How long does it take to upload hounder of files? How long does it take to download a new file to your PC?
Or if it hogs your network or CPU usage: some client software can make the PC nearly to a halt.
And don't forget to protect your data in the cloud:
And if you do chose cloud provider don't forget to protect data in the cloud by replicating files and data between cloud services: