Never used the -B, but my bass board always has a BF-2. It's impressive how it can do that - it's great for bridges or set subtle to contrast between verses and choruses and add a little shifting movement in the low end. And the frequency range works so well on Bass VI-type instruments.
A little more time to play and compare the clone to the OGs: the clone is good and is cut from the same cloth, but definitely a bit flatter than either my early or late model Boss boxes. Would have been senseless to buy when BF-2s were only $40, but now that the price gap has widened, seems to be an affordable way to get close. But maybe not the slam-dunk replacement the ELady seems to be for an Electric Mistress. Will still get plenty of use on my live board.
Nevertheless, a tasty little flanger.
The Boss is still the boss.