Targeting Astromech is basically PTL for Hobbie off K-turns. Do a red, assign stress, get a TL, lose stress, take your focus (or VT barrel roll) action, profit.
I played a few games with him lately and found the hardest thing was finding that perfect lane in the scrum to just K-turn over and over like a TIE Defender. If you can get there, he's good. If not, he doesn't get to do his tricks and just dies as a wasted investment.