Regardless of what one thinks of Courtney as an actor, casting him as Reese was a mistake and shows a complete lack of understanding of the character. It would have been akin to Arnold playing Reese in the original film.
What really pissed me off about Courtney was how arrogantly dismissive he was about Biehn's performance.
I've said it before but I at least would have had more respect for the guy if he put in the work. Anton Yelchin also had crap to work with but that kid worked his ass off and made you believe he was Reese. Or even Courtney's co-star Jason Clarke, who went back and watched T2 because he wanted shades of that little boy we saw in that film, reflected in his performance.
Either way, the movie was a failure and we won't be seeing anymore, so it's irrelevant.
Courtney's moved on to Suicide Squad and he's working with a director who actually knows how to utilize him and in a role that actually fit's his personality.