Other than size and BC, I don't see the Boyle comparison. Boyle had a nasty game right from the start. Over a PIM a game as a freshman, then 1.5 as a soph, 2.5 as JR and SR. He started to show some offensive skills as a JR but other than 1 year in the NHL it never really translated. With him it was "If he improves his skating and hands he can be a good 3rd liner, but if not he'll be a physical grinding 4th liner."
Letourneau is a better skater, more creative, better hands. If his offense progresses he can be a good 2C. But if his offense doesn't progress, I'm not sure what he is. His faceoff skills are good so I guess he can still be a 4C, but I think he'll frustrate fans as a big guy with no offfense and no nastiness. And if he turns into that, who really cares.
I agree with DKH check back in a year. But the kid has a LOT of work to do.