I only use Guss when grouped with a non-healer for heroics.. I have always used Risha (once I got her) to burn through the groups much faster than any other companion. She's dps like Akaavi, but I could gear her in my hand-me-downs. Sure she takes a beating in the medium armor, sure I can pull aggro off of her when I try, sure I normally have a couple seconds of healing after a tough/rare/champion mob fight, but I still found it much faster than Guss.
Here's my strategy in case you want to try it yourselves:
Target the toughest mob
Tell Risha to attack it
Target the weaker mob(s)
Attack
Kill the weaker mobs
Tab to Risha's target (if you're fast enough Risha's still alive)
Attack and try to pull aggro before Risha dies; more dps to down it faster if she barely lives
Pop a defense cooldown, use push-backs, stuns, etc if needed...you have a lot of skills, use them all
Dismiss and resummon Risha
Recover your own health (may not be necessary if you killed fast enough)
Tab to forums and give this advice to other die-hard Guss only users