Ask Cubanito about the cali press. I don't know about them but he does.
JM press is like a close grip bench, but you don't lower it all the way down, and you don't lower it to your lower chest/upper abs area. You lower the bar toward your collarbones/upper chest area, and stop the bar about 5 or 6 inches above your chest, then let the bar drift toward your head about one inch and press back to lockout. It is about 15 or 20 percent tricep extension and 80 to 85 percent press.
Paul 's press is done on the floor, lower the bar with a close grip till your elbows or triceps are on the floor, then bring the bar toward your head 3 or 4 inches then press to lockout.
I personally think that the JM press is far superior, I have done both, but I have dropped the Paul 's press, because it is really tough on my shoulder, and does not seem to hit my triceps as hard as the JM press.
Hope this helps,