IMO, the dominant variable in the Roth vs traditional discussion is length of time in the market, and thus, what fraction of the nest egg is from earnings vs your contributions. Contributions from a 30 year old will double 3 to 5 times from market returns before they retire, which means a Roth has the potential to shield upwards of a million dollars of earnings from taxation forever.
For someone who is a year from retirement, the Roth vs Traditional can become a wash. One year from retirement, you are probably earning the most you have ever made, which means a Roth contribution will be paid out of the highest marginal tax rate you have ever been in. Furthermore, those contributions won't be in the market long enough to earn big market returns.
My plan is to make traditional contributions up to retirement, and then backdoor convert to roth in retirement like crazy, up to the point where I would start hitting the 22% fed tax bracket. The main goal there will be to dodge RMDs if I live long enough where I would be forced to make gigantic withdrawals.
H