From what I can tell (and I'll confirm this when I get on later), BB is one of the higher damaging katanas with a 'standard' moveset now. Top three at least, I think? I was expecting it to be, but I can't say BB's range has been too much of a factor in PvP, surprisingly. I murdered the Twin Princes with it too. The 2H R2 is telegraphed from Mars but the tracking catches people nicely. Of course, it infuses and buffs too (though standard seems to out damage any of the former from what I can see).
WP's base damage has been reduced post-patch to around 411-418 uninfused (at 40/40, I think), so it isn't quite the beast it once was. Other katanas are much more viable now.
I believe CB does pretty good (if not the best) damage, especially for pure DEX, but has the usual HP drain effect which you have to use a couple of ring slots to offset, and only then by a little bit. Can't buff or infuse it either.
You know all about the Uchi. It is the lower end of the damage charts and has the standard moveset/range.
Now Bloodlust... I wouldn't say it's a Chikage knock-off (I wish it was!); the moveset is pretty standard for DS3. Again, not dipped in too much because the 30% damage bonus from WA and short range don't seem worth it to me. You get the buff for 15 seconds or so (I think), a flat 200 damage to yourself (I think) and your bleed metre cranked right up. Seems like a terrible trade off on paper. Maybe a very aggressive playstyle with hyper mode (ToD, Morion and RTSR) on would work nicely with it but I've not tried that. Yet.
The only other katana is U&O. High damaging for quality builds,
evil dual moveset, great chase down/roll punishing WA. This one is a beast, though it lacks the awesome standard katana WA and is obviously only available very late game.
As far as I can tell, Darkdrift sits somewhere in between all these in terms of damage, range and moveset (depending on what the patch changed, of course). It can't be infused or buffed, unfortunately. I can't see it being anything other than a reliable workhorse (in both good and bad terms) but it's definitely stylish! I'll give it a proper go today and see what I can get out of it.
Like I said, I'll happily pop down some accurate damage and scaling stats when I'm on this afternoon, if you want.