When one partner spends too much in retirement!
#1: I've been doing a lot of analysis for clients on Roth conversions. The success of the strategy depends on your situation BUT let me be clear it works very well for many people. It's a powerful way to create significantly more future wealth that will be subject to less uncertainty and risk. Note that the strategy can work so well that it's worth paying high tax rates to do it while you're still working. The article on backdoor Roths below is related and a way to shift even more into this powerful structure.
https://www.businessinsider.com/backdoor-roth-ira