Coruscant is soloable, just keep your companion out, and run from it when the chain attack goes off. It turns from a 1400 dmg per second move to a 1 dmg move. Just keep moving during the fight and you will pwn SD-0.
I have done Taris, Nar shadaa, and Tatooine as well.
50 Watchman Sentinel with Centurion/Champion gear.