Ketsu is cool because he might tractor on the Snap Shot with the title, at start of combat with his ability, and again with his normal attack with the title. That's both more chances and the ability to stack to tractor larger ships. Snap Shot is a forward arc at range 2, which is decently easy to line up, and he's a higher init.
However, Asajj is pretty solid. 2 force points for attack and defense is useful on its own, and foresight is more accurate than Snap Shot if you can line up the bullseye... though I can tell you, bullseyes on fat ships can be hard. And if you're fielding Asajj, it's tempting to equip Hate instead. That said, Asajj is solid on her own, so she's not a bad choice with Foresight.
Ketsu is more tractor-focused and wants to be shorter range with his turret always forward. I can see that working out, just like Asajj, but I'd have to try both to see which I like better. I do know Ketsu has seen more table time overall where I play, while I haven't seen much Asajj for a while (the Hate nerf hit her pretty hard). And right now init 5 counts for a lot.