I love this card.
1.) Tarn with an R7 is stupid durable, I think that much is clear. I'd even go so far as to say he's the best 25 points you can spend in the game.
2.) A generic X Wing with R7 is not far behind Tarn in survivability provided you correctly guess which ship is going to be shooting at which x wing, which gets easier if your opponent has less ships.
3.) Biggs with R7? Probably the best defensive Astromech for him IMO, also cheaper than the others besides for R4-D6 or whatever that weird 1 point unique one is.
But what I'd most like to point out with this thread is a subtle thing about the card and lists built around it that makes it surprisingly good.
So, when playing a non-R7 ship, ideally you'd want to TL first incase you roll well this attack, and save it for when you need it/combo it with focus. However, this comes at the cost of unmodified defense dice on the turn you choose TL instead of focus.
With an R7 however, what happens is that now a TL also doubles as a defensive action. So you can dump TL's first turn with no consequence, and if you don't need the defense it stays during the cleanup phase, unlike defensive focuses.
I guess when I put it that way, it's kind of obvious, but the R7 helps you out much more than forcing your opponent to reroll his hit hit hit focus attack, it optimizes your action economy by giving you a defensive action that can be saved until it's needed, and you still have the option to use it offensively. A defensive target lock sticks around after you K turn, sticks around when you bump or go through an obstacle. If your opponent rolls like crap and you don't need a defensive modification it isn't wasted. It also stacks with defensive focus, so it adds another layer of defense to an otherwise fragile X Wing.
You get the flexibility of the focus token being usable on either defense or offense with the optimization of action economy the TL provides by not getting discarded at the end of every turn.
Oh, and another thing. It's better to reroll incoming attack dice as a means of defense than reroll/focus your own defense dice, you're more likely to stop hits that way due to evades being a 3/8 chance (5/8 if focus) on agility dice and hits being 4/8 (6/8 if focus).
Edited by ParaGoomba Slayer