I was surprised to see no mention of the California state championship game in this forum, since it was on Time Warner.
Based on this one game only, Preston looked short, he was inaccurate, and did not show a particularly strong arm.
He was not one of the top 5 players on the field in this game.
On the positive side, he showed he's good at catching bad shotgun snaps, which is a must to play QB at SMU.