.....but as I generally prefer maximizing compounding of equity gains by deferring tax payments as long as possible ...
Compounding of equity gains really isn't a relevant factor... it is totally a tax arbitrage play. Let's say that you have $10,000 in a tIRA and the relevant tax rate is 12% and investments double in 10 years.
If you convert and pay $1,200 in tax then you end up with $8,800 in the Roth and in 10 years it doubles to $17,600.
If you don't convert and the $10,000 doubles to $20,000 and you withdraw and pay 12%/$2,400 in tax then you have $17,600 to spend.
So you equity gains don't matter either way... what matters is if there is a difference in tax rates between today and tomorrow... which is nil in the example above.. so there is no particular benefit.
If you use the same example and the tax rate today is 12% but in 10 years will be 22% then if you convert you end up with $17,600 but if you don't convert you end up with $15,600...$20,000 * (1-22%)... so where your tax rate today is better than your tax rate later then you are better off to convert. It's that simple.
On the Kiplinger article, let's look at them:
No. 1: If You Will Be in a Lower Tax Bracket in Future Years... agreed... it's the inverse of what I was explaining above... if it is beneficial to convert when future rates are expected to be higher then it would obviously be disadvantageous to convert when future rates are expected to be lower.
No. 2: If You Don’t Have Enough Cash or Savings to Pay the Conversion Tax... I wouldn't agree and the example above proves that even if you pay the conversion tax from the conversion that you still come out ahead if your tax rate now is lower than your tax rate later. For many people, between ER and when pensions and SS start they will be in a lower tax rate than they will be once pensions and SS start.
No. 3: If You Might Need the Money Within Five Years or Less... no necessarily... if you are over 59 1/2 you can withdraw conversions out tax and penalty free... but if under 59 1/2 then I would agree.
No. 4: If You Plan to Leave Your IRA to a Charity... totally agree and we often refer to this... the reality is that many here have very significant tIRA balances that even with aggressive beneficial Roth conversions will still have significant balances left over for qualified charitable distributions.
No. 5: If Your Beneficiary Will Have a Lower Tax Bracket Than Yours... agreed and we often talk about this here as well. In my case DD and DSIL are in a higher tax bracket than we currently are but DS is in a lower tax bracket.
No. 6: If Your Estate Isn’t Large Enough... I'm not sure what their point is here but I haven't heard that people do conversions for estate tax benefits and it woudl rarely apply anyway... people do it for the income tax benefits.