I have tried it before and never have invisible units near me been visible until they attacked. What is it good for?

This is quite useless.

i agree. i've never had it show an invisible unit on the radar. any ideas?

I found a use for this spell.
Saving you 70s at lvl 24.

This Ability is not working. It is currently broken and hopefully they will fix it soon. No point in even using it at the moment. It's really a shame because we should have some kind of defense against rogues, or at least be able to track them a bit better, we are hunters after all.

It shows them when there close, but not on radar. But at least I can mark and send pet against them first. I'm lvl 30 Tauren hunter and find it good in Ashenvale and Thousand Needles against all those hiddens. If you're too low lvl like 5 under I think, it won't work.

For one thing they have to be your lvl or lower im pretty sure. It didn't work for higher ones for me. Also its not like other tracking abilities. Basicly if u get close enough you will see them.

Is this ability truly worthless, or is it only worthwhile against PCs? i've heard conflicting reports...

it would be nice to know, so i can take it off of my action bar. :-)

and to the person that said that they can see the hidden a little better with it on: You can see most  stealthed NPCs anyhow. if you want to see them better, use flare. at least flare works like it is supposed to. :-)

Also the REASON i know you can see stealthed NPCs is i play with a guy that is legally blind, and even he can see the shadowmaw panthers and shadowcats that are around, at the same time i do, without me using anything at all to track/unhide them.