Can I copy the folder in 8.5 to the folder in x-2 and use the effects>?

No need to copy -
 
Just add the file location of your 8.5 VST's to the X2 scan location under "Preferences", and rescan...

thanks ! why didnt I think of that !

No problem!  :)

Hmmm...  I thought the shared plugins folder was for the older DX/DXi plugs?
 

There should only be 1 Shared Plugins folder and it has nothing to do with VST plugins. It's the older DX plugins that are system installations not SONAR specific in that the folder is in the Cakewalk branch of the folder tree not further down in the SONAR X1 or X2 branch. Hence the ne Shared Plugins.