Boomerang is a very interesting Icebreaker-alternative. It's too early for me to have done a full analysis on the new hardware, but it seems like a very useful tool in any deck that wants to run hardware and trash cans (so Az and Geist). It can outright let you walk through some of the most annoying ICE in the game for a mere 2 credits and an install. It doesn't matter if your surveyor has 30 strength--Boomerang breaks it for 2 .
[Edit in light of clarification on hardware uniqueness thanks to Mezuzi]
There is a bit of Corp counterplay though that Boomerang users should be wary of. It's unique, which means you can only have one installed at a time. If you use it to mark an unrezzed piece of ICE that the corp can afford to leave unrezzed (or even over-install the next turn) then your Boomerang just has to sit there, doing nothing until you spend another 2 , a card and a click to overinstall a new one. This now means that in total you've spent 2 (4 if you count each card draw as a click), 2 cards and 4 credits to bypass 1 piece of ICE -- definitely not a good deal, especially if it means some of your hardware/trash can triggers were delayed at the same time. The icing (ICEing?) on the cake is that it also can't recur itself, so the Runner is down 1 Boomerang in their deck. Of course, they probably have recursion somewhere that brings it back, but early on it might be an option to nab a scoring window.
I'm sure new ideas and better analysis will be discovered as time goes on, but for now I would say this is a strong and fun card to have to in the pool.
...if you're a Runner.
Both Corps and Runners are allowed to install multiple unique cards in general - it's just that older unique cards get trashed during the next checkpoint. Your friend might be misremembering the "Limit 1 console per player." rule that is written on consoles that would prevent the start of an install of another console.— Mezuzi
@Mezuzi -- Thanks for the clarification! I've updated the review to reflect this.— Chezni