Do C.S. Lewis Arguments against utilitarianism hold?

They are as follows, if I remember correctly:

1. Granted that laying down one's life so that other people continue to live is good, why should it be ME that sacrifices his life? Why doesn't someone else do it?

2. Since being dead means never having to feel pain, is it better than to never have been? Which is more moral to seek, that which increases happiness or that which diminishes pain?