All stats items vs 3 stat items
Many people ask about multi-stat items but it depends a lot on your character’s build. For example my warrior has the Empowered trait which gives 1.5% extra damage per unique boon I have on me. When partying its beneficial for me to have runes that improve my boon duration to take advantage of this and the boons themselves. There are also traits that take advantage of, for example, having a lot of vit and therefore any points invested in vit may yield further advantages.
So personally I wouldnt be looking at just the stats themselves, but how you can use those stats. If you dont take advantage of what ive mentioned above then maybe it will be beneficial to go for multi-stat items. I would, however, stay away from the Triforge as its massively expensive and will probably be replaced during the next ascended patch. Im fully expecting to see ascended earrings and necklaces next time around.
Retired and living in a shack. Relaxing!
Its a trade off you have to make. A glass canon build is one extreme and the other a bunker build. Using all stat items lie in the middle. As Thereon suggests it is more about what you want. If you feel your to breakable add some toughness and/or vitality. On the other end use power/precision/crit for direct damage. Or go for condition damage and power.
Your play style is also a part of this, if you are good at dodging and have a reasonable amount of cleansing ability defense is of less concern and you can add some more offense.
Choosing a specific stat and getting all upgrades/items for that will give you a high capability there at the cost of the others. All stat items give you an average overall. It is mainly a mater of choosing that stats that fit your character and play style.
On my staff elementalist I have a toughness power mix giving me good survivability in WvW against any class while still being able to do good damage. In that build condition damage, precision and crit damage are not as usefull.