The Calibur has the advantage of having one of the best charge attacks in the game right now. You move at normal speed while charging, and it hits a full 360 degrees around you. Cornered/heavy enemies will often get hit multiple times as well. As a default go-to weapon if you're only carrying one blade, I think it's pretty much unmatched.

The Brandish line, on the other hand, are probably better weapons overall in the right situations. The fact that they do elemental or shadow damage will result in much higher damage against the appropriate enemies, and their added status effects can be very useful. Their charge attack is also quite good, though perhaps not in the same way as the Calibur's. Because of their special damage types though, you will need to make sure you're carrying something else to hit things against which your chosen Brandish isn't effective against. That can be a problem if you're still working with the default 2 weapon slots, but it isn't insurmountable. (It's also much less of a liability in a group than it is solo.)