Powerful tool in the right hands.
Most common mistake is to consider it's ability as merely rising cost of ICE breaking by 1 per counter. It's an enormous waste and if you are the one playing so, consider some other 3-pointers. This card is a taxer, stopper and a killer, if the opportunity arises. You should basically read it's ablity as: "Hosted agenda counter: Runner loses one ." At least.
Consider Eli 1.0 - the guy's biggest wekness is being a 1.0 Bioroid, which means he can be passed through with two clicks. Breaking it for cash is expensive and eventually Runner will try click through... But now you can add a third ETR subroutine. That means that either the Runner must spend an another - providing he has one. If not, he MUST use the breaker - providing her can afford it... This way you can force Runner to spend, or stop him dead if he is out of clicks. Three times in a row.
With upgraded Bioroids things are even more interesting - Ichi 2.0 has more stiff clicking cost, requiring spending in pairs. Now, when facing him, Runner must consider either to use an expensive breaker or face TWO effects at the cost of .
Project Wotan, as it's name suggests, works best with the Big Guys - titular Wotan supported by his agenda has effectively five hard ETRs. And when the Runner gets to face his fears, you can now think of your agenda counters in terms of brain damage!