Just played a couple games against my friend, XXBB vs. TIE Swarm (Howl + 4x 3-PS TIEs) + Soontir.
My two B-Wings were both like this:
2-PS B-Wing + Advanced sensors + Engine Upgrade
I found both B-Wings to be rather useless. I used Advanced Sensors and Engine Upgrade to do some arc-dodging but the sheer number of TIEs meant it was possible to dodge some but not all of their arcs. The B-Wings' low PS coupled with their weak agility and lack of Evade means that they are very easy to kill. One of them got killed in the first turn before it could even do anything. The other got killed shortly thereafter.
So, I am wondering, do low PS B-Wings stink? Or am I just not using them correctly?