I have not used a Sako 85, but I do own Sako 75s. While the barrels of the Sakos and Tikkas are the same, all other components are different. While Tikka is an excellent gun, the Sako is in a class above the Tikka. While the Tikka uses quite a bit of plastic/synthetic components, the Sako essentially uses none.
Both guns shoot great. The Sako is about double the money of a Tikka. The Sako uses about double the cost of its components (because metal is more expensive than plastic). Have I ever had ANY problems with my Tikkas? Never. Have I ever had ANY problems with my Sakos? Never.
Bottom line - you can't go wrong with either one.
Zachary