What a stroke of luck that I saw this. I didn't have notification turned on, I haven't logged-in for months, and just randomly decided to.
Anyway, iDrive. Well... unfortunately I can't recommend it wholeheartedly, but maybe with some caveats/reservations.
It's a tremendously ambitious product and I think that's where they're falling down. It tries to do local and cloud backup, sync, mobile backup, disk imaging, cloud file sharing, and more, across multiple platforms (including, as I said, mobile). And their prices are generally competitive. Which means they're trying to do more stuff within the same revenue envelope/profit margins, which generally means corners will be cut. In this case I think the corners are cut in both Support and Development/QA.
What you end up with is a product that, when it works, works decently but not exceptionally. It is programmed (seemingly) in a functional but not clever or elegant way. Functions like deduplication are simplistic or outright missing/not working, for example. If you move a file to a new location it has to re-upload it (last I checked, admittedly it's been a few months since I did, I just stopped worrying about it). When it does a backup it has to scan all your files again and it takes ages with large file sets, even though the app is running all the time and theoretically should *know* what has changed already. The realtime backup is a separate function from the normal backup.
Perhaps one of the most important things is that the notification system for failed backups is *part of the application itself*. This means if the application fails to start for some reason (as happened to my mother for many months recently), then you may never realize it and your data could be not backed up without your knowledge! This contrasts with Crashplan (and presumably many other providers, though I don't know for sure) which have the cloud platform itself, i.e. your backup account, notify you if no data comes in for x days. I still get notifications from Crashplan that I haven't backed up in like 9 months.
Other than that silliness (I stopped paying ages ago, why hasn't my account been deleted?), the idea of notifying from the cloud account makes tons more sense because then you know if your local application is not doing its job! If you rely on the application to notify you, your likelihood of failure is much higher.
The big problem though is that while these issues are generally fixable (in some cases it seems it should be fairly simple to fix something, like the notifications for example), when you report them to their support you generally get nowhere. Support is bad in my experience, and that's a problem. I am really just hoping that their dev team is actually working and improving things and that with time it will get better enough.
In the end for me there are just very few real options. I have a very large amount of data, over 3TB with millions of files, and I don't have a bidirectional gigabit connection nor $100s of dollars to spend every month for backup. If price were not a concern I might use some kind of AWS-backed setup since they have an option to mail physical disks for initial data seed. But given price sensitivity, iDrive is one of the very few options that offers data seeding (for free no less!) and that also does local+cloud backup. The fact they do a lot of other things is interesting and sometimes helpful too. I've actually used the cloud file sharing a few times and been happy it existed, even if it's a little clunky. But I'd happily sacrifice that and some other functions for a more reliable and well coded core app.
That being said, Crashplan - one of the few other options - was just consuming way too much memory, and had its own reliability issues at times as well. iDrive works *most* of the time and does its job adequately, as far as I can tell. If I had less data or more money, I'd probably recommend something else (not sure specifically what). But given my needs I'm still sticking with iDrive for a while longer to see how it develops. If they can deliver on the promise of their app+service it could actually be incredible. Having all these features in one app *could* be great if they were all well developed and reliable. Let's hope they get there...