Looks like a real top-6 to me right now.
He played against men in the Liiga at 16 (only 18 games and 4 points but still),
17 (.66 ppg) (that year, Jokinen and Turris were about ppg in the same league) and
18 (.61 ppg) being the best scorer of his team.
Then he went to SHL and followed the same path. Playing two more season with men rising to the top during PO.
Koivu and his coach know he is not coming back.
I think we should expect 35+ points from him this season and would not be surprised to see him getting nearly 50 points a la Gallagher (had a pace of 52 points in his first season under MT (the coach that destroys young players)).
SHL (.57) >> AHL (.48) so using the translation ratio his ppg in PO you get .57*82...
Do the math.
He had about the same numbers as Teravainen in Liiga at the same age.
Difference is that Teuvo came to NA and played with the Hawks and in the AHL while Lehkonen improved in SHL.
One thing for sure, with Radulov on the second line, he will get at least 35 points.
Edit: BTW according to Habs site, he is 183 cm and 79 kg.