As for "AI"...
I actually think Ace does have a voice, but I think he's trying too hard to be "new" and "hip" and "different". He sounded like he was whining through the song last night - even to the point of being nasal and unsupported breath-wise. I'm guessing he was going for that sexy, breathy sound, but it just wasn't working. And he needs to stop working those eyes, that whole final "sexy stare" at the end of his songs is just getting too too.
And did anyone else notice that in the wrap-up clip, they used a different clip than the "live" performance? His falsetto was actually stronger and more on pitch in the clip than it was on the performance. Mandissa also had different hair too in the wrap-up, and Paris' clip sounded different too. I know they do rehearsals beforehand, so...