My kick serve is still effective against 4.5+ but I have to mix up my serves more to keep them off balance. Against 3.5-4.0s, I can just roll kicker after kicker to the bh wing and force errors or short returns to put away. Against 4.5+ you need more variety. I have to hit my spots and mix up the speeds and spins with flat, slice, top and kickers otherwise they can just camp out in one spot because they know what to expect and can set up to crush the return.Yeah...there's only one person who says 3.5 hits harder than Nadal or that a 4.5 strokes would be indistinguishable from a pro during practice. I'm not going there. As for you, anyone could see from watching 30 secs of your clips that you'd be sandbagging at 3.5.
My point is what you put in previous post. How you had a great kick serve that seemed to work against 4.0s, but against 4.5s, not so much. That's where I was going with this. To achieve a deadly kick serve at the 4.5+ level that will get you easy points or a clear advantage, is not an easy thing to do. Then to have the confidence to do that in clutch situations time and again, requires even more skill and confidence. You might as well just got a pretty average 2nd serve in...one that didn't require a ton of practice. That's all I was trying to say. Also, once again, if you have the time, goals, and ability to get to that rarified air where you can consistently hit a great 2nd serve..more power to you. I never said that ones who had the ability to do that should not.