Nope, with Backblaze you have instant access to an individual file. Here you need to unarchive your safe, which can take up to a few hours (depending on the size of the vault), and only then you have access to the content of the safe. No way to retrieve only 1 file, or have instant access.
It says on the page that there's a 7 days window during which your data is freely accessible and mutable, after which it is permanently stored in the homemade infrastructure.
Each of the drives in a Vault has a standard Linux file system,
ext4, on it. This is where the shards are stored. There are
fancier file systems out there, but we don’t need them for
Vaults. All that is needed is a way to write files to disk, and
read them back. Ext4 is good at handling power failure on a
single drive cleanly, without losing any files. It’s also good at
storing lots of files on a single drive, and providing efficient
access to them.
We upgraded the Linux 64-bit OS from Debian 4 to Debian 5, but we
no longer use JFS as the file system. We selected JFS years ago
for its ability to accommodate large volumes and low CPU usage,
and it worked well. However, ext4 has since matured in both
reliability and performance, and we realized that with a little
additional effort we could get all the benefits and live within
the unfortunate 16 terabyte volume limitation of ext4. One of the
required changes to work around ext4’s constraints was to add
LVM (Logical Volume Manager) above the RAID 6 but below the file
system. In our particular application (which features more writes
than reads), ext4’s performance was a clear winner over ext3,
JFS, and XFS.