Ive been playing DAoC since release and in that time have played almost every Albion class there is. My primaries are a 50 Scout and a 50 cab.
Now as a Scout ive noticed that most casters dont notice im shooting them until my 2nd shot (the 1st being stopped by the BT) and sometimes, by then, its to late.
As a caster (my cabalist) in RvR I also almost always fail to notice when someones shooting at me in some form until the 2nd shot lands. ESPECIALLY now with NF and the RA system they have the fonts which everyone seems to love using en-mass. So these, plus group buffs, enemy spells, friendly spells, ect. I dont notice the BT icon dissapearing. Now it can be argued that yes, it reports when your getting attacked. But if there is any combat/death going on in the emediate realm its easy to miss the report.
So what I suggest is this: Provide some form of graphic showing that your BT has been popped. Hell, show a bubble around the caster accually popping. Maybe add a popping sound to it. Something that makes it obvious that, yes, you are getting attacked and you'd better do something about it.
Just a though. I appologize if this has been discussed before.