Ropo makes a lot of statements about the effectiveness or otherwise of various machines. Listen, I am a designer of gym equipment. If you think it is easy then have a go at designing something original and new. Talk about 2% difference is pure speculation.....in polite terms you don't know what you are talking about.
Things might look similar but could be substantially different if compared properly. You don't want to mess around with dangerous exercises for the triceps because it is too easy to damage the connective tissue and you can end up with sore elbows that is more or less permanent. I can tell you variations of tennis elbow is no joke. If you do standing French presses with a barbell you can get sore elbows. Experience will tell you which exercises to avoid and which are okay. Sometimes okay exercises get to be dangerous if heavy weights are used. Little things like arm pads and side pads can make all the difference in the world. Why? Well, believe it or not almost all people cheat doing exercises in the gym. There are two things fuelling the lack of good form in exercises. One is the ego which sees just about everyone trying to use big weights so they look strong. The other is the belief that using heavier weights will result in larger muscles. This is only partly true. The requirement is that the target muscle is actually lifting the resistance.
Two days ago in my gym I found 2 young guys doing the lying triceps extensions. The shorter bloke was using 10 X 5kg plates. He wasn't a huge guy so I told him there was no way he could use that amount of weight. So he proceeded to show me that he could. Fair dinkum, the guy was doing 1/3 range reps and his elbows were sliding sideways. Also, his shoulders were rising up. His body wasn't in a strong position, either. So I got him to reduce the load to 6 plates and have another go. He was struggling to do the reps. Eventually, after several adjustments on the machine, he was successfully doing 5 plates! He could feel the difference and now appreciates how to use the machine and get some results. His mate was taller and he ended up using 4 plates instead of 7. I told both that if they could genuinely lift 10 plates for 10 reps they would have much bigger arms.....18" cold.
I solved the problem of the body rising during triceps pressdowns by installing a bar that allows the user to put his foot under and that keeps him from rising. Made that in the early 1980s. Previously we used a heavy dumbbell to do the same thing.