I took a double Defender list to a charity tournament this last weekend and had a lot of fun with them. My list (if anyone cares) was:
Rexler Brath
Juke
Jamming Beam
Collision Detector
Proton Rockets
Countess Ryad
Juke
Jamming Beam
Collision Detector
Cluster Missles
I had the most fun, and success, when I was able to cycle the Defenders in and out the the battle. I would set up Rexler to joust and the Countess to flank. On the second round Rexler would duck behind an asteroid and the Countess would turn in for a range 3 shot. I was able to get my opponents to generally chase after one while the other circled around for another pass. The Collision Detector really caught people by surprise (and saved me from some poor flying). It let me escape a few traps as well. I had 2 win and 3 losses so it was not the best list out there, but very enjoyable. The 4 K turn and 3-5 speed moves were obvious choices that people expected and set traps for. So it was interesting to try and find better moves and I was often able to do that. Sometimes the 4 K was just the best move and I could take the damage for a round. It was not easy to eliminate enemy ships though with only two fighters of my own. I guess I don't see any need for changes, its fun, it can be blocked, it can win and it can lose. Just my two cents.