I come up with $684,847 with starting balance of $100,000, 8% growth over 25 years in an IRA or 401k...assuming no inflation and no expenses. An assumption of about 1.47% expenses would give me the $475k. I missing something here...

yobria said, "If the 100K goes into a taxable account, you lose $25,000 off the top, and pay a 25% tax on short term/interest gains the year you incur them. Person B makes such investments, and pays the regular tax rate on 75% of his gains each year. After 25 years, he winds up with $323,418."

how does this relate to the 401k/IRA? seems like apples & oranges. if one is to use a taxable investment as a retirement vehicle why would they be impacted by short term gains? They should be touching the investment correct? btw, why would they lose $25k off the top? If the $100k is coming from some savings account (I'm assuming here...) why the "$25k off the top"? Taxes would have most likely already been paid on the $100k right? I can understand the taxes on any gains but not on the principal which I assume is the $100k.

I like the Person C example as many forget to include the fact that one can use a loss harvesting strategy to limit their losses and get a little something back from Uncle Sam...

I agree with your conclusion but can't seem to reconcile the calculations from your assumptions...Not sure what pieces I'm missing.