We are 69 and 67. Our pensions plus Social Security plus dividends (etc.) thrown off by mutual funds put us into the middle 22% bracket -- even before I take SS next year. Conversions don't make a lot of sense for us, IMHO.
The only argument I've seen that I considered seriously is preparing for widow(er)-hood, when one of us will be vaulted up into the tax bracket stratosphere. I've decided that's far enough off to not be a worry now. I-ORP (before it went dormant) agreed with me -- the difference between aggressive Roth conversions and none at all was very minor (a few $1000 per year).
In other words, we have too much income
-- not the worst situation.
I can see the value of conversions if your pre-RMD / pre-SS income is in the 12% bracket, and you'll be pushed up when those income sources hit.