D&D 5E (2014) Rarity of a customized magic item?

[CapnZapp]

By the way, this is an often overlooked advantage of wielding a single greatweapon. You only need to spend one Attunement slot where sword and board fighters and dual wielders will have to spend two.

 

[MarkB]

By the way, this is an often overlooked advantage of wielding a single greatweapon. You only need to spend one Attunement slot where sword and board fighters and dual wielders will have to spend two.

Well, simple "+x" weapons and shields don't require attunement. And if you get something more specialised, then you are gaining some additional properties in return for that attunement slot.

The main advantage for the two-handed wielder is that they don't need to find an additional magic item.