You are right that not everyone benefit from conversion.
Several factors need to be considered -
1) There is "Minimum Required Withdraw" for IRA when you turn 70 1/2, this will increase your income (even you don't need it) therefore increase your tax rate.With ROTH IRA, even your kids can get them income tax free.
2) IRA withdraw is counted as "ordinary income" therefore you can't enjoy the preferred tax rate on "long term capital gain"; besides, preferred tax on "LT capital gain" may be changed.
3) Your future income may not be decided by your "needs". Some of us have large position on 401k/pension/annuity, they all have required withdraw amount.Gov't may increase tax rate in future; Your tax rate is NOT necessary lower than what you have today.
Always, use simple excel to list all pros and cons. For most of us here, it may be better off to convert with strategy (not convert 100% at one time).
