I recently gave the current build of Xenonauts a try a liked what I saw. I know a lot of this stuff is still WIP, but I felt like giving the time increments some scrutiny.
In my opinion, the current increments are a little on the thin side and I dislike the way the buttons stretch from an tiny square-like button to an extremely long button. Functionally, each time increment is equally useful and I feel the variable button sizes imply 4x speed is vastly more important than 1x. This and because you're constantly switching back from 2-4x speed back to 1x when waiting for UFOs and base building, I think larger, same-sized buttons is better.
I felt like going with 1x,2x,3x,4x buttons instead of >,>>,>>>,>>>> is not only simpler, you don't need to make the last button extra long, as you can see from the trouble I had fitting the >>>> into the alternate designs. What do you guys think?
EDIT- Alright, a slight update, one variation using filled in triangles and the other with numbered increments w/o the x's.