jquery/jquery — comment on commit 166b9d252a025009413eee1584dc364996dcb1c2
File:  line 0
By rkatic:

It's more about correctness. Consider:

function Record(name, id) {
this.id = id;
this.name = name;
}

$.param({"boo" : new Record("foo", 666) });

Why to unnecessarily to make this not invalid?

Also, an more honest perf would probably be http://jsperf.com/type-vs-isplainobject/2.