My party rogue is a retaliate/riposte mace build, so I found it a pleasant surprise.
The other soulbound weapons are two handers, so it was probably a balance issue. Their procs are pretty nasty and if you combine that with dual wielding...
It's not balanced at all. For example you have 3 two handed soulbound weapons (gSword, Estoc and Quarterstaff) one Mace and one bow. That's not an even spread at all. Or it would have been, to some degree, if I could bound any weapon to any class. As a dual-wield barbarian I would have been satisfied with the mace.
At any rate, I would have liked a better selection, or a more wise one.
I doubt the wisdom was there when selecting this first set of soul weapons.
The estoc and great sword overlap the type of damage dealt. Though, in the estoc's case, is curios that the new rouge has all the attributes requirement for the dialogue, is already dampened in movement by his unique armor and the estoc at full power is able to add two different sneak attack conditions for the rogues (which have a feat which increase sneak damage when 2 or more conditions are meet).
A monk is stuck to a staff (which overlap with his prime type of attack), but can't use the bow.
The mace is not a fast weapon but an average one, so is not useful for two weapons character with high dex (ok, that can be debatable).
The great sword seem to be linked to paladin (yet I sold by accident the item, so never got to its fully potential).
The special lighting damage of the bow, seem to be unique, maybe with my cipher I could take a chance (Can't remember if can be used by them).
But truly, the most WISE thing do by Obsidian was with the staff: IF you already completed the game, the only creatures available for the second condition of the staff ARE IMMUNE to the staff damage (at least you has an item/feat property that let you add elemental damage, and yet will be almost minimum).
And only the estoc and the bow were interested or better than my custom weapons :(
Maybe a full replay taking all those weapon in consideration could make a big difference, but better to wait to second part as Santiago suggested.
P.d. with the patch 2.0.1 the requirements between each level are symbolic now (Good thing as this game don't respawn the creatures)