With all due respect, your code seems to be a copy/paste of my code, where you've removed the Pair and Option implementation (allowing the alternate default I discussed in my second blog post) and replaced my string `ColumnarVec` with your string `SimpleSerialize`. So, thank you for measuring my code for me? :D

The reason the new numbers look better for Option with the Copy implementation is that you are now writing 16 bytes for each Option. They are a 50-50 mix of Some(0u) and None, which I wrote out in 5 bytes on average (always a 1 byte "present/not", and then 4 bytes of data on average). The Copy implementation is just writing 3x as much data and padding the throughput numbers, rather than reporting something more like goodput.

I sense that this isn't the right place to shake this out, so I'll stop posting. If there is a better way to follow up, let me know.

[edit: I've got you through github, thanks! I'll buy beers when I swing by TU next]