What is a indicator for good items/weapons?

[Trojan.Exploit.SSX]

I often find weapons/items with higher level or quality, than I already equiped. But the indicator shows red down arrows. Even Legendary Items are sometimes worser then some yellow stuff. Can somebody explain me, what is a good indicator for items/weapons? Also is there a difference between Level and ItemLevel? They always show the same value.
Last question: Does every class use the same stat to deal more damage or does this differs from class to class?

Thx for response. :)

[Trojan.Exploit.SSX]

Nobody there...?

[unknown2000]

Well, I'd say the best way to be sure about which item is better is to compare all the stats. There might be boots that have very high defense, but boots with a high speed might beat them if that's what you're looking for. It all depends on how you want to build your character.

[Albertafox]

Ive no idea how the system works now.
There are many items that are clearly not upgrades.(+5str is better than +50int for white mage?)

You can see the weird bias with lower lvl items since they do not contain multiple stats.

[Trojan.Exploit.SSX]

I was asking because I found 2 legendary boots. First with level 29, second with level 32. In the preview (red/ green arrows) the level 29 boots was in every category better (damage, armor, energy). So I was wondering why the low-level item was better than the higher. So how does the game handle this quick-indicators?
And why is Level and Itemlevel always the same? What's the different? :)

[Sol4rSky]

The mage doesn't benefit from strength from what I recall. His damage scales based on int / energy