I really don't get the UR hate - it just doesn't break down under any logical scrutiny at all. At least I haven't heard the logic...
What's the difference between UR and a 4-second hard stun ability (assume, hypothetically, that a mara has a choice of either)?
With UR the mara is getting cc'd, taking a little damage (no joke - I've died several times from damage while under UR) and the mara is swinging away (if he's not cc'd). So far so good.
With a 4 second stun the mara is swinging away, not taking any damage (you're stunned) - he can't be cc'd by you (because you're stunned) _and_ he's getting healed if he has a healer on him, omg.
Ah, you say... but I can pop my trinket ability during the hypothetical mara 4-second stun. That is true - that's one def every two min (or so) to stop this hypothetical stun. But, you can always stun or kb or root/snare a UR affected Mara or you can vanish/sprint away or pop heals/defenses of your own or do any number of things - lots more options vs the UR mara - almost all with lower cooldowns than the trinket vs the stun.
Are healers afraid of maras running up to them and hitting their UR button? NO (they would -laugh- and hit you with a dot if you pulled that in a 1v1). As a mara, I would much much much rather have a 4 second stun than UR. UR is nice because it lets you pretend your a god when you're fighting 5 people and got them all to focus on you but it's a very short-lived feeling.
And let's not forget that while a stun never costs the caster of the stun anything, the caster of UR loses half his health. That is not something you spam for fun.
Note, if we're talking about a 2v2 or a 3v3 or a 4v4 situation and the mara is getting heals while popping UR every 45 secs... why are you attacking the mara at all (or -any- dps) and not the healer(s) and/or tanks?
You don't understand your ability very well at all. If you died while using it then you must have clicked it as absurdly low HP and if you ever lose 50% health when you activate it then you need to L2P. Using it at full health is LOL.
And FYI there is a LOT of difference between UR and a stun ability. How can you even compare the two? Really guy? You really don't have a grasp of your class if you would trade UR for a 4 sec hard stun.