I am agreeing with you and confirming the same results.  Isn't it nice when two people come to the same conclusion?

Net results for me...
It works great until block 1781476.  It then runs into an error.
If I had to guess though, I would say this is when the client hits a kind of 2GB windows file limit, an error is flagged and the client then goes into syncing mode instead of importing blocks from the bootstrap.

Further issue is that my client must be restarted many times as it simply stops syncing. (Both when trying to rename the bootstrap back or simply to let it run through normal syncing.)

I am currently at:
Sat Jan 6 20:13:52 2018
1851170

It wouldn't be so bad if the client didn't need to be restarted all the time.