not really. high-speed USB communication (USB 2.0) goes up to 480 Mbps
the math should be:
you transferred 1000 bytes in ((endClock - startClock) / 106 ) seconds
so in 1 second you transferred 109 / (endClock - startClock) bytes
which seems to be what you have
To get to bps you would need to multiply this by 8 (8 bits per byte) but there are also more stuff being transferred in the protocol, so actually more bits are really pushed out.
PS: @UKHeliBob
I would tend to agree with @lsi8 on this
topics were related but different questions and now the title seems to say the discussion is about the bug, whilst it's about data transfer speed. The reference to the previous discussion was a helpful hint for those willing to duplicate the test that they needed to alter the current build to include a patched flush() version.