No matter what you won't tax protect all 18% in your 401k if you're making CA pay, top widebody FO pay or I/E pay once you hit the max compensation limit of about $345k. If you can push that to CBP you avoid upfront taxes on it and for many of us, you eventually pax taxes in retirement after it's had a chance to be invested (59.5) and you're likely in a lower tax bracket. If RHA is your thing great. If not PRAP cash is great except you're getting slammed with your marginal tax rate. But do recognize that the latter parts of your 17%, soon 18% are not going to be going into your 401k once over that comp limit.