As a convert, I really do not consider the word at all insulting. In fact, I believe the word is useful, and this is a matter that I have discussed with my priest on occasion. Depending on how, why, and from what the individual converted, the person may still be inclined to view things through the filter of his or her former teaching than through an "Orthodox" mindset. This is particularly true when the person converts from a belief system that does a good job indoctrinating their members, and has a good parochial education system. This does not mean that the person is at all bad, but only that certain terms mean something different in different belief systems.