I don't know if they are over rated...its the only way ive seen cheap guitars stay in tune through real whammy abuse.There is alot of crap for double locking trems out there though(low-end ibanez/jackson/bc rich/esp e.c.t)...besides the kahler's(which are tough to find) the original floyd rose/pro or ibanez edge/pro really are the best floating trems.