Like most of these lists and will try a few as I love the Defender but how much does VI help in your games? PS8 just doesn't seem all that useful unless you see a lot of Dash maybe. I keep trying to find a place for calculation and some of these lists with VI seem like a place to squeeze it in. Annoying that you need to use your focus but at one point, if you can drop a crit at the right time it might be worth it.
I'm just mentally replacing "VI" with "Adrenaline Rush" everywhere, but you could pretty easily do Calculation, too.
...pitching for AR again, it completely changes not so much how you fly a Defender, but how your opponent has to react to your defender. You don't really fly like an Interceptor, but your opponent has to treat you as if you do, and that's a lot of fun.
And completely aside from that, you do have the option of a white 1-turn once, which in the middle game can turn a knife-fight completely in your favor.