5P+ is a much improved 6010 over the original 5P. Lincoln added something to the flux to make them burn smoother but I can't remember what. It should say one or the other on the package but 5P isn't seen too much anymore. Strangely enough 6010 need about 5% moisture in the coating. If the rods are burning kind of funny, try dipping one in water, wiping it off and then welding with it. The moisture won't affect the weld. 6010 generally use less heat than 7018. A 1/8" 6010 uses about the same heat as a 3/32" 7018 but another way to set your heat it is to strike an arc and push the rod right into the plate while it's burning. If your heat is too cold, it won't keep an arc. This is how a lot of pipe welders set their initial heat for doing root passes. They may need to tweak it a bit but this gets them in the ball park. Once they try welding on the pipe they can adjust their heat as required. 6010 takes a little more practice to get the hang of.