Excerpt: [The] new products -- call them hybrid 401(k)s -- combine guaranteed income in retirement with an investment portfolio. There's no simple way to do that, and the products vary greatly in their structures, features, and costs. We spoke with retirement and insurance experts about what they think are the best features for these pension-like 401(k)s to include, as well as potential pitfalls in their construction. Here's their thinking on six key criteria.  MORE >>