A good comparison for Gunnarsson is his countryman Hjalmarsson.
Careers:
Gunnarsson (26, 6'2" 195lbs): 224gms, 12gls, 69pts, 301ht, 420bk, 20:32 (82gms, 4gls, 25pts, 110ht, 154bk)
Hjalmarsson (26, 6'3" 205lbs): 306gms, 9gls, 56pts, 196ht, 570bk, 19:05 (82gms, 2gls, 15pts, 52ht, 153bk)
Last 2 Years:
Gunnarson (26, 6'2" 195lbs): 113gms, 5gls, 34pts, 192ht, 223bk, 21:34 (82gms, 4gls, 25pts, 139ht, 162bk)
Hjalmarsson (26, 6'3" 205lbs): 115gms, 3gls, 25pts, 68ht, 236bk, 20:28 (82gms, 2gls, 18pts, 49ht, 168bk)
Both tall, rangy guys who can skate and move the puck. Gunnar does have a bit more puck skill but his minutes and scoring edge in these numbers is mostly due to more opportunity on the PP than Hjalmarsson gets in Chicago....neither of these guys is much of an offensive guy, and both play a similar role against similar quality of competition.
Gunnar is a bit more physical, but it's also true that the ACC is a little more friendly for hits stats than most other arenas. The blocks numbers do indicate that both guys have similar role and dedication on the defensive end.