Yeah it's a bummer you can't custom enchant it but Bound sword is awesome and the enchantments it has with the perks are awesome.
Bound Sword Pros:
Soul Trap+Banish Undead.
It doesnt add weight and you can carry more loot
Looks Awesome
Bound Sword cons:
Casting/Sheathe Time
Less Damage
Daedric Sword Pros:
More damage
Custom enchantments
Can temper for extra damage
Sheathe/Unsheathe
Daedric Sword cons:
Enchantments don't have infinite charges
Weight
I would use the bound sword to fight conjurers or when I need to soul Trap, but I would use the daedric sword as a main source of damage.