Since I'm sticking to resistance based toons, I can only shed light on what defense is in pvp at the moment since it's probably the best way to answer the question.
Under the assumption that you've been fighting awhile, you've probably seen what diminishing returns does to powers. So, defense also gets bumped down.
I have a widow that has 60ish ranged defense in pve after using mind link. With DR, it gets bumped down to 40ish. Against normal enemies that do not have +tohit active, such as build up or aim buffed, the defense does pretty well at 45%+.
However, since most builds have a +tohit such as build up/aim, toggle tohits, click tohits, and stacked rages.... your defense becomes rather useless unless fighting a flimsy build or you have elude up your sleeve.
If odds are in your favor for a 1v1, go with the defensive build at the 45%+ range after DR and unleash as much damage as you can before your life eventually gets whittled down.
Champion/Freedom Servers
@Orion Zidane
@Orion Zidane2
Def is almost useless unless you a way to take down your opponents to-hit.
Defense is ok when it's something like Elude levels of defense. Anything less is basically not even noticeable. And some people will hit you with every single shot even through elude.
How much defense is good in PvP? How much should I am for?
@Real Boss
Real Boss-50