I had them as a kid. I needed them but more for having teeth that weren't too overcrowded. It was worth it. I haven't worn a retainer since the Reagan administration and I still get compliments about my teeth from my dentists.
That said, there can be unforeseen drawbacks. Not just the expense and the experience going through them, but I've heard of cases where jaws got slightly misaligned to where their jaws sometimes "pop" more, etc.