Tax Brackets and IRA choices
1) If your marginal tax bracket will be higher in retirement then a ROTH is the way to go.
2) If tax brackets are the same during the working years as when you take the money out...
then one dollar [earned, invested in a deferred tax plan, and then withdrawn in retirement and taxes then paid]
is exactly equal to :
the one dollar[ earned, paid taxes on when earned, invested in a ROTH plan and then withdrawn in retirement]
provided the term is the same and the investment rate gain is the same.
3) IF marginal tax rates go down in retirement then go with the deferred plan. If marginal tax rates go up in retirement then go with the ROTH.
Good luck with predicting your future tax rates and future tax policy some decades out ! If your income is at least what you make now then I would predict that your retirement income tax rates will be at least as high (or higher) than they are now. MY magic 8-ball says that for you perhaps the ROTH is the way to go.