As said, the gravelord sword is one easy to get and pretty strong early weapon, but is harder to upgrade than others.
The black knight sword + 5, easy as hell to upgrade and without needing any ember, it's what you want, without many stat investment is just a bit weaker than a +15 claymore with ideal stats (27 str, 40 dex) which means a lot of soul levels and the need of large and very large embers, imagine how imbalanced is that thing for now.
Low stamina usage is listed as a con? <_< Low stamina usage is a good thing.
Also, the damage is pretty good for a weapon of medium to small size early and moderately through the game. Also, two-handed, its R1s aren't moderate in speed at all. They actually chain together to be some of the fastest weapons in the game. Painting Guardian Sword, a weapon with the same moveset, actually has the highest DPS potential of all weapons.
It kinda sounds like you specifically wanted a BIG weapon. Whereas Jagged Ghost Blade is entirely the opposite. It's compact, and it has essentially no stat requirements, so anyone can use it.
Also the bleed is pretty powerful, since as I said it can hit pretty fast. So you can tear up a lot of enemies.
Have you tried it on many enemies? It should be pretty damaging, especially for its speed, unless you have weirdly high strength/dex for the early part of the game you're in.
I am snazzier, hot, hot rant. Warily slight as. Croak rush, OK? Weirder, almighty make out. ::)