I use both Crashplan and Backblaze. Just be aware that if you are backing up terabytes of data (in my case ~9 TB) the initial backup can take months. Can't remember exactly how long mine took, but it was in the 3 - 6 month range. My sense is that Backblaze does the initial backup much faster, but for some reason iStat Menus didn't seem to show Backblaze network activity during it's initial backup so I can't confirm that and I don't remember how many months it took.
Backblaze has a list of files that it excludes. The default list includes directories such as Applications, Library, and System but you can easily change them. It also has a list of excluded file types that it will not back up:
wab~,vmc,vhd,vdi,vo1,vo2,vsv,vud,iso,dmg,sparseimage,sys,cab,exe,msi,dll,dl_,wim,ost,o,qtch,log,ithmb,vmdk,vmem,vmsd,vmsn,vmss,vmx,vmxf,menudata,appicon,appinfo,pva,pvs,pvi,pvm,fdd,hds,drk,mem,nvram,hdd
You can edit this list.
Crashplan doesn't have such a complex exclude list.
Crashplan is more configurable. For example Backblaze just allows you to backup continuously, once per day, or manually. Crashplan has a continuous option, but a "between hours" option as well. You can also specify the verification intervals, frequency and versions. etc. I believe Crashplan will also manage backups to a local disk.
A Backblaze restore can be done via a zip file, in which case the system preferences pane which controls the program directs you to their website where you select the files to download. Once the files are ready they send you an email.
They will also send you your files on physical media. They charge $99 to send you a zip drive which handles up to 128 GB, or $189 for a 4 TB drive. If you return the drive within 30 days these charges are refunded. You are responsible for shipping charges.
Crashplan restores are handled within the Crashplan application via download. I saw no option for a physical media restore. This could be a significant issue if you are restoring terabytes of data. I tried a small ~1 GB restore and it took about an hour. That means a complete restore of my ~9 TB would take over a year.
I have had a coupe of technical issues with Crashplan. The default amount of memory which is allocated to the program will handle up to about 1 TB of data. If you are backing up more you have to edit the configuration file to allocate more memory, which is not a big deal.
Because my backup set is so large the default verification configuration takes such a long time that a new verification starts before the last verification is completed, so no backups are done. I changed my verification period to 3 weeks and that fixed the problem.
I rate Crashplan's support as excellent as the two issues above were immediately resolved by support. Backblaze support was also good the one time I used it.
You might also consider SOS backup. I believe that it's initial backup is faster than Crashplan or Backblaze. However it turns out that my 12 cpu nMP breaks their program, so I can't confirm that. This would not be an issue for systems with fewer CPU's. I would rate their support as excellent as they have been very responsive in working with me to resolve the problem. Development just hasn't figured out what it is yet, but that should only deter people who are running 12 (or maybe 8?) cpu systems.
So Backblaze is a bit simpler to configure, but I am a little nervous about all of the exclusions. But a full restore would happen a lot faster via physical media than with downloads. I prefer Crashplan's configuration options, and the fact that it is an app rather than a system preference panel. However disaster recovery might be a problem due to the slow restore speed. SOS Backup looks encouraging, but I unfortunately am unable to evaluate it at this time as it won't run on my system.
The general rule is that you want to have 3 backups on 3 different media types (such as tape, disk, or at least disks from different vendors) in 3 different locations. I don't remember actually having to do a restore from Crashplan or Backblaze, but it is good to know since it's been 110 years since one of our major faults (the San Andreas) slipped. When it does all of my equipment is going to be thrown over 9 feet. I just hope it's not against a wall or thrown at me ....
