It's a nice quick and dirty trick to align knkwn data, but that's a bit unfair to compare it with column(1)... In this case you have to assume your first column to be shorter than 12 chars. It is totally input dependant, as opposed to column(1) which aligns up to the longest string of each column.

You'd have to soak up your whole input before rendering anything, and measure your longuest input in some way (which I don't think sed can do).

I know you manipulate awk(1) auite well, and I think it would be better suited for this task!

Thanks for sharing though! Still interesting to see that kind of solution!