Even though Kurri was better defensively than most give him credit for, Forsberg was on a whole other level in that regard to the point where he could be a game changer in either end of the ice.
That is a surprising assessment as Kurri was considered to be one of the best two-way forwards in the game. While not indicative of playoffs, they both have one second place finish in Selke voting and I would think Kurri is ahead in voting overall.
I have heard that if he was not scoring 50-70 goals per season, Kurri would have gotten at least one Selke. Forsberg was more visible and physical, one probable reason for his injury troubles I might add, but it is arguable if he could have played like that in the 80's.
Anyways, I should probably watch some of the 80's Oilers playoffs again to refresh my memory. Last time I watched their first Cup-winning series against Islanders some year ago or so, I was extremely impressed by Kurri's overall play on both ends of the ice and especially his absolutely lethal shot.
I would not put Kurri or Forsberg clearly ahead in either offense or defense. However I think the former has an edge by being the leading goalscorer in 4 SC winning teams and a key part in another SC winning team while provinding (according to contemporaries) Selke caliber defense. I do not know how much more playoff stud one could be.
While no fault of his own, Forsberg was injured in the second SC winning team and had (to his standards) surprisingly underwhelming playoff production in the other SC winning Colorado team. I think circumstances work against Forsberg more than his actual ability, but nevertheless I cannot penalize Kurri for making most of his opportunities.