re: Benefits of a Roth 401K vs a Traditional 401K?

It's a way to hedge your bets, to have some in a traditional and some in a Roth. In addition to the tax deferral differences, Roths don't have RMDs.

Also, someone noted checking on the match provisions. If a company does match Roth deferrals, note that the match will still be in a traditional account, even if your deferral is a Roth. The only way around this, and I don't know of any companies doing this, would be for the company to tax the Roth match, essentially phantom income. I would not do this.

But if you are trying to split your total match plus deferrals in a certain percentage, keep that in mind.