I thought of porting an 850 KB xdelta patch to BPS. It takes under a minute to create the patch with Xdelta -9.
BPS wants 35 minutes and 16 GB of RAM to make the same patch. And no, those aren't miscalculated values.. it almost crashed Windows. Had to terminate the process after 10 minutes. It claims to be a direct competitor to the xdelta format, even says it produces smaller files, but this is unacceptable!