The Garmins then.
Almost guaranteed.
I suspect that neither the Wahoo or Hammerhead will be perfect, but both will be better than the Garmin at slightly different things. I'll probably keep both.
@Velocio started
London Fixed Gear and Single-Speed is a community of predominantly fixed gear and single-speed cyclists in and around London, UK.
This site is supported almost exclusively by donations. Please consider donating a small amount regularly.
The Garmins then.