Originally Posted by
Allyrion
For monks and dragoons, for examples (it's what I know), weapon equates to roughly 7.5 str.
Using the monk set as an example
The relic+1 is 2 weapon damage increase which is equivalent to 14 str. If you add the actual strength on the gear (which is an increase of 4), you get an upgrade of 18 in your main stat.
The Melee cyclas (monk chest) compared to the darklight chest has a difference of 9 in strength.
So the Relic+1 is twice of a main stat upgrade compared to the upgrading the chest piece. I believe all dps classes have a similar result, with the exception of bards who have lower weapon damage or something.
Weapon damage is everything to dps.