Thank you for the link, MDM. I read the thread and concluded that continuing to invest as I do now is preferred vs saving in roth accounts exclusively. Under my current formation, I paid <3% federal income tax in 2017 and expect the same in 2018. If I switch to all roth accounts, I'll be paying between >12% but <24% annually. Believing I'll be in the 12-24% bracket during retirement, I appear better off deferring while I actively work.
I also attempted to read the Bogleheads marginal tax rate thread, but found it too technical. For my reality, my current salary will be what I earn for the rest of my life regardless of how it is received. I typically receive a 1% annual raise, but no lump-sum bonuses or promotion pay increases will significantly alter my taxable gross income y/y for the next twenty years.
I maxed out both my roth IRA and traditional 401k this year. ~$500 was removed from my September paystub as income taxes.