I watched a replay of a Gio start vs the Jays recently. It was a highlight game for him, but Bautista was out of the lineup. He went 8 innings, and was left in with 1 out in the 8th and a runner on 2nd with a 2-1 lead. He struck out the final 2 I believe.
As for the repertoire, decent velo on the FB, around 92. He is a bit of nibbler on the outside of the plate. He didn't throw inside very often. I thought he did a good job changing the eye level while living on the outside of the plate with a FB, curveball combo. His curveball is a sight to see.
OAKLAND A'S TV - "CURVEBALL" - YouTube
That video pays it homage. He had the Jays whiffing at everything and kept control of the lineup throughout the game. The Jays were hacking.
I also watched some of a poor start to see where he gets derailed. I watched him vs KC, who according to the broadcast team hits him well. He tried to establish the inside of the plate and gave up HR, HR, 2b to start an inning. His FB just isn't that hard to hit, so if he misses just a bit, it was getting tatooed.
I really like his curveball and other breaking stuff. I think he locates his FB better than Volquez, so if has control problems my guess is it isn't due to "wildness" like Volquez, who sometimes doesn't know which pitch has a remote chance of being a strike. Not sure he's worth a haul of prospects, honestly, but his high K numbers and really pretty breaking stuff makes him an upgrade and a sure #2 on the Reds. A really enjoyable #3 if Leake or Bailey can command their talents.