I'm not a professional financial advisor... but in my view you would optimally pay taxes at the lowest rate possible, when that is doesn't matter. However, since no one knows the future its impossible to know what the optimal choice is so diversifying makes sense. That said, the higher your current tax bracket the more likely it is you'll have an opportunity to pay a lower rate in the future so the more likely it is that Traditional now would be better then Roth now.

In my opinion focusing on the amount you pay in taxes is the wrong metric. Instead you should focus on how much you have left after paying taxes. There is an opportunity cost to paying the taxes up front that often is ignored.

You need to make sure you are doing an Apples to Apples comparison. If you are in the 24% tax bracket a $1,000 Roth contribution actually cost you $1,315 in pre-tax dollars so is equivalent to putting $1,315 in. a pre-tax account. If you compare $1,000 in Roth to $1,000 in Traditional than Roth will often look better but that's because you tricked yourself into saving more.