I use Max 5x and I've been getting quite a lot of value out of it. Claude has completely taken over maintenance of a few side projects I wasn't putting much effort into. The projects where I do the work myself, I use Claude for code review. My usage patterns are mapping almost exactly to the 7 day window, so I'm consistently getting 100% of the usage I paid for without having to wait a long time for the rollover.

I've never used Codex. Can't compare the two.