I use all +damage enchants on my gear. I have changed my spec so much that I am not sure what I'll need most at some times, so I gem my gear appropriately and then just pour on the +damage in the enchants. For example, when arcane, you don't need nearly so much +hit, so putting that on glove would not be a good idea. If you will only ever play a single spec, then that's different, but I have too much fun with the various aspects of magery that I tend to respec at least once a month. ;-) (also, testing the new stuff like LC + MSD for arcane and the like).