Definitely. I've been hoping for the addition of his riffs and lyrics ever since he'd rejoined the band. Let's be honest, a little bit of fresh air in the lyrical department could only help the band (even if I'm not a fan of metal lyrics in general, I used to appreciate some Testament lyrics; sadly, the new ones mostly seem bland). And Gene's clearly one of the best in this field (Time Does Not Heal, anyone?).
The same goes for the music. Not that the crew in charge doesn't do great, but it's a shame to have the talents of Gene and SDG and not utilize them in the writing process and mix things up even more.