Mega offers true end-to-end encryption, a responsive smartphone app, and great upload speeds (tested in Europe). However, the service has an essential flaw: The desktop app allows accessing the user account on the Web without additional password verification. That means that if you lose your computer, someone finds it, and plugs your hard drive into his computer, he can access your Mega account. From there, he can delete files irreversibly. He can even download the recovery key. In other words: When your computer is compromised, so is your data.
That may seem natural, but then again: what is the purpose of a cloud backup if it is no more secure than your computer? What Mega should do is require the password (or at least the second factor of 2-factor-authentication) before granting access to the user account. I explained them the problem and the proposed solution, but they replied saying they do not believe Mega has a problem.
The issue can to some degree be mitigated by installing not the desktop app, but only the command line interface MEGAcmd. This interface does not allow clicking through to the Web interface. But even then, an attacker, a malware, or you yourself (by accident) can execute mega-rm -r -f /. This command will delete the entire remote storage, the entire local storage, all backups, and all version-history of all files. The rubbish bin can be emptied similarly. Thus, a command of only 15 characters can annihilate your entire local and remote storage.
The only solution then appears to use Mega's rewind feature. I have not yet tried it out.
I have not tested for the desktop app backdoor. However, iDrive fails on another criterion: it does not allow collaborating with other users. First, it does not allow sharing folders with other users in order to work together on the same data. Second, it does not even allow sharing download links to files and folders (this works only for non-end-to-end-encrypted objects).
You may want to ask why it makes any sense to share data that is so private that you keep it end-to-end encrypted. The answer is that there is data that you want to share with a friend, but with no-one else. That is where end-to-end encrypted sharing comes in handy.
Furthermore, iDrive keeps only 30 versions of your files. That may sound like a lot, but if you work on any document for an hour, and you have the habit of saving it frequently (as you should), then chances are that you cannot go back to how the document was an hour ago.
The drawback? The mobile phone app is painstakingly slow! (At least when you access it from Europe.) Navigating into a folder can take 10 seconds — meaning that going into some 6-level structure takes easily one minute. Watch the video on the right to see how frustratingly slow it is. Note also that Sync first shows files and folders that no longer exist, and notices this only when I try to open a file.
I was a long-time client of Sync.com, and I still believe it is one of the best services out there. However, the app is just too slow and buddy. So I finally changed to Mega. I admit it's a game changer: I can get work done on the phone. I can sort pictures (unthinkably slow in Sync), share links to files (possible, but slow in Sync), arrange files and folders (unreliable in Sync, as the first video shows), and even edit text files (impossible with Sync). So, yes, hello Mega!
If you want to give it a try, use the link below. It gives me a commission without costing you more: