The in-game descriptions are as follows:

Warlord's Dragon Armor:
-protects against all damage types.
-reduced healing from life spells.
-great decrease in movement speed.

Epic crystal staff:
-massive bonus to cold and ice spells.
-greatly weakens fire and steam spells.
-greatly hastens focus regeneration.

Soul screecher:
-medium physical damage.
-knockdown.

Robe of riviera:
-protects against all elements.
-protects against chilled status.
-can go beyond walls (breaks walls).

Crow staff:
-massive bonus to earth spells.
-massive bonus to cold spells.

Silver longsword:
-medium physical damage.
-medium knockback.
-improves troll slaying (huge damage against trolls).

In my opinion, the robe of riviera (and its equipment) is the superior of the two. It's quite overpowered in fact.