I agree with the O/P that Harvey may well save many lives in Irma.
One big difference though is this. Houston is the 4th largest city in the US. I do not know if, in the early days, they did not think it would get this big (likely) or if they did not care (Unknown) But the city was NOT designed with evacuation in mind.. Most cities in Florida are 1: Smaller (All of them) and two designed with Evacuation in mind. making it easier to get out of the way. This is good.
Still there are going to be those who DENY the science and stay put.. I hope they survive. but fear they won't.
Best place to take shelter in a hurricane (Official government quesiton)
A: Indoors
B: Outdoors
C: Under ground
D: IN a shelter outside the storm area
(Correct answer is D of course... Oh, and I passed the test).