I've looked at many backup solutions and IDrive came out on top.
They offer 5TB of storage for an unlimited number of devices at a price that's cheaper than most other services. The "unlimited devices" is important (and relatively rare in the online backup space) because I can back up my multiple computers, my Android, and my iPhone all using a single IDrive account (each device's backup is separated, but accessible to all so you could restore a file from one computer to another if you wanted).
Other services offer unlimited storage but limit you to a single computer. That was a non-starter for me, but may make sense for people with a single device and over 5TB of storage needs. Also, with other services, assuming there's even a mobile app available, often it's just for viewing your backed-up files, not for actually backing up the device it's installed on. The IDrive mobile apps allow both.
The computer software took a few tries to get right, but after getting it set up it's rock solid. I can specify what folders/drives I want backed up (or simply the entire computer), specify files and folders (with wildcards) that I *don't* want backed up (e.g. temp/tmp/cache) and can set the entire backup on a scheduler. Notifications and status emails are sent about each backup.
There are also optional security features that I've taken advantage of.
The first is that you can use your own private key that causes the files to be encrypted locally prior to transmission. That means that nobody - including IDrive itself - can view your backed up files (technically, they could most likely view the file *names* but not the actual content). It's not the default, and you have to choose it prior to doing any backups, so pay attention on the initial setup. You can use the default, which is to use an encryption key that IDrive creates for you. The data would still be encrypted, but it does mean that in the unlikely event of a rogue IDrive employee or stolen key somebody else could view your backups. You can always switch later, but doing so means "resetting" your account which deletes all of your current backups and makes you start over (which makes sense).
The second security option is to enable multi-factor authentication. Every time I log into the application I need to verify it by entering a code from the Microsoft Authenticator mobile app (I believe other options like text codes are available as well).
Both the private encryption key and multi-factor authentication are probably overkill, but the slight inconvenience means nobody except me is going to be seeing my backups - something to consider with any online solution.
As far as tech support, I did have some questions about the application behavior and getting things set up, and tech support was very responsive. You have to create a support ticket via the web site, but after that communication is via email. Response time was a day or less for the initial contact, but very quick after that, sometimes within minutes. Responses were sometimes a little scripted, but helpful and reps were quick to escalate when necessary.
Finally, backup times were very quick. Granted, I have symmetric 1GB fiber internet so upload speeds are pretty quick, but I did try SpiderOakONE backup solution and the upload speeds were horrible with the same connection. I've upload around 2TB of data from 2 machines to IDrive in a couple of hours.
Overall, IDrive is quick, stable, offers a generous amount of storage for the money, allows unlimited devices, and supports backup of computers plus phones. The default privacy options are good, but optional ones are even better. I wish the PC software was a little more intuitive, and access via the web version is lacking (but luckily you can do most everything via the local applications).