Items with damage add vs. stat adds

[Corvidia]

Hi folks,

I have a level 39 priest with shadow spec. I have been looking to see if anyone has done any testing of the effect of items with stat bonuses vs. damage adds.

What I mean, is that I understand that damage add items add damage on a 1 to 1 basis. That is, if I am wearing gear that gives me + 80 shadow damage, then my shadow spells will do + 80 damage (either all at once for direct damage spells or over the term of the damage over time spell).

I also understand that spirit is a bit buggy but that it aids mana regeneration and that INT adds to your total mana pool.

My Q is whether it would be preferable to have damage add items or INT items. I can hunt mobs at my level and drop two of them with a full load of mana. I then drink a water and regen back to full, wash and repeat. I know I would have more mana available to me if I had more INT items, but each spell cast would then do proportionally less damage without damage add items. Does it all equal out?