Excellent discussion. I did some research.
I have been using the traditional 401k, but I think this year I will switch to Roth 401k. I have also been doing the back door Roth IRA for both my wife and I, since 2012. If you are not doing this, you should.
Why am I going to do the Roth 401K?
For one reason only...
At 70.5, you must take mandatory withdrawals from your 401K, even a Roth 401K.
But, you can convert your Roth 401K to a Roth IRA, and then you don't have mandatory withdrawals.
I read in the WSJ, that people smarter than I are not leaving their Roth IRA's to their kids. They are leaving them to their grandchildren and great grandchildren, if they are able.
Your heirs get the money tax free, and must take mandatory distributions based on their lifespan. So, giving it to a 5 year old is smarter than giving it to their parents. Smaller distributions, and longer time to gain interest.
I have instructed my wife to spend the Roth money last, and only if necessary. If she can, I want her to leave it to our grandchildren.
Sometimes, it pays to think long range, like a forester.
Thanks for all of your thoughts.