When comparing SpiderOak vs BackupPC, the Slant community recommends BackupPC for most people. In the question“What are the best backup programs for Linux?” BackupPC is ranked 7th while SpiderOak is ranked 12th.
Specs
Ranked in these QuestionsQuestion Ranking
Pros
Pro Combines cloud syncing, storage service and backup client
Thus you have a single service for all of the things.

Pro Available for many platforms
The Spideroak client is available for Linux, MacOS, Windows, Android and iOS.
Pro Incrementals
SpiderOak updates only that part of the file that has changed, saving bandwidth and time.

Pro Zero knowledge
Data is locally encrypted before uploading to Spideroak. They cannot recover your data even if they wanted to since it is stored in encrypted state on their servers.
Pro Unintrusive
Pro No need to install anything more on the backed-up PC
Pro Able to handle large amount of servers and data
The disk IO can be a bootleneck but the system itself handles even multi terabyte servers easily.
Pro Supports various platforms
Backup method is highly configurable, using local copy, ssh, rsync, SMB or custom transfer, so able to backup almost any OS supporting these.
Pro Open Source
Pro Efficient disk format
The disk format automatically deduplicates files, and optionally compress files or assist recovery with redundancy information (par2); storage disk usage is very efficient.
Pro Combining full and incremental backups into "filled" view
Backups are always viewed as a whole, regardless of the count or data content of past incrementals.
Pro Rich command line tools
Apart from the Web UI there are command line tools for doing all tasks related to the backup system.
Cons
Con Version 3 on-disk format is impossible to "file-copy"
V3 format uses hard-links which is almost impossble to "file-copy" (using filesystem level tools like cp or rsync) on a large system, since the hardlink management eats up vast amounts of memory (the only way to copy a backup server is to copy using a whole-disk copying method). This has been fixed in version 4 format which uses pointer files instead of hardlinks.
Con Web UI timeouts on large amount of data to be displayed
The Web UI needs large amount of time to walk a directory with thousands of entries and it may cause the webserver or client to timeout. Large directories may require the admin to use the command line tools to list or restore files or directories.
