Maximum viscosity for the current iSub G/Apex coils?

As the title says I am wondering what ratio of juice (ie. 50/50, 70/30, MAX VG) do you recommend for use with the current coils for the iSub G/Apex? Can the coils hold up to max VG juice or would you recommend something thinner along the lines of 50/50 PG/VG.

Also, I am just now seeing the Prism coils and am wondering if they are different then the original coils, and if so how? Thank you!