Specular/Gloss Materials Question

[Banti]

I have a question regarding the difference in specularity on different materials. Say i have these Materials:

1) Glossy Material
2) Diffuse Material + Specular Layer
3) Universal Material with specular setting
4) Universal Material with coating

If i applied the same settings for specular (same IOR, roughness etc.) to these materials would the final material be the same in every case?
And is there a difference between specular and coating on universal materials?

Thanks