As an employee of a BCHL team and general fan of the league, I've seen Turris play probably ten times since he entered the league, and quite simply, he destroys the competition. I think he's a better prospect than Zajac was at that age, having seen both play.
No one in the league dominates quite like Turris does, and he doesn't coast either just because he's better than everyone in the league, the guy works extremely hard every shift. Burnaby is a lousy team this year, and he's really only got one other decent offensive threat on the team, Tyler McNeely, who is a pretty decent player in his own right, but he's 19 and not nearly at the same level.
Espo has played against much better competition, but I wouldn't discount Turris because of that. However, I still think Espo is a slightly better prospect, but I would've liked to have seen Turris be invited to the Canadian junior tryouts, just to see what he could do against this country's (U-20) elite.
I'd be surprised to see either slip out of the top-10, but Turris could be a big faller because he plays Jr. A.