One of my old company's customer seriously asked the support what's the difference between ">=" and "="...

Support should have answered that one is faster than the other :D
But life must be hard enough anyway...

'">=" is faster but many prefer the looks of "=" therefore it is better code style
so ">=" ist used for performance critical applications while "=" is used when readability counts
">=>=" is just to many characters which increases the memory usage so despite the possible performance gain people usually use "==" instead if they want to use all cores of the CPU for the ">=" operation
for security critical applications one should go for "!="'