I could agree that in some cases born-ins are better off within the org but I don't see the point in comparing them with born-outs. I think that the born-out's path is far healthier.
A born-in will live a life of deprivation, of social awkwardness and in many cases he will stay in just because he didn't dare to look anywhere else. And if he eventually leaves the org, he will feel that he hasn't gone through several life stages that are completely normal for a non-JW and that are indeed important for self-development.
A worldly person who later in his life joins the JWs, even though I think it's a complete lie, he would make that choice freely with far more knowledge and having previously lived all that there is to live in "the otherside".
And if we are talking about if it's better for a born-in to stay or leave, I definitely say leave. Despite the initial feeling of inadequacy or lack of life knowledge, nothing is more valuable than living your life freely. Indeed, as a person who has lived behind so many barriers, he will be able to appreciate that freedom more than a regular person.