I love Phantasm for leveling, but now at 50, with a solid build, all my incarnate powers and buffs, perma Phantom Army, and Oil slick arrow as my big damage dealer, Phantasm is just a chore now to keep respawning. Don't have time for him. I have enough to click with TA. lol. On teams, or solo (at 54x8), he just dies every mob nearly, and I don't have a heal. Oil slick arrow and Phantom army keep me steamrolling. Really the Phantasm for me isn't much of a difference maker, with or without him. Except more to click.
Now that is me, with my build and with Trick Arrows.... if I were Illusion/Rad, or maybe dark...sure... Phantasm may be far more useful and sturdy. No doubt!