Delta restore is now available!!!!

[admin]

I believe (only a guess here), since HBS uses no special changed block tracking driver, they are using the $MFT timestamp method for their DELTA operations.

Funny thing about this: HBS is faster in creating incremental images than Reflect, I can do incrementals in seconds and it's saving data at almost 4 GB/s in my test.
So if HBS really doesn't use any drivers for keeping track of changes, it probably should never do so. It just works

But let's wait for an official answer first 

Yes, we don't use changed block tracking driver (We can't get the driver signing certificate, thanks Microsoft.), so we can only compare timestamps. In fact, there is another problem with using changed block tracking driver, there is no way to track block changes in Linux, unless the backup software provides a changed block tracking driver for Linux.