As usual, multiple things can be true at the same time.
In the few series we saw of Miles O'Neill, against a nothing team in NMSU, he looked poised and capable and led the team to the endzone. That doesn't mean too much, but you want your guys to look dominant against bad competition and he was trending that way.
He's also got one of the stronger looking arms we've seen in the last decade in Aggieland. There have been plenty of QBs with cannons who didn't amount to anything, but if you're asking if being able to put the ball 50 yards in the air on a rope is a good thing… yeah that's a good thing.
Ideally, as he's just a RS Fr, we get a couple seasons of great play from Marcel and then hand over the reigns