have the garmin varia and a garmin unit. sounds like the crossover garmin/wahoo thing works which is awesome.
varia has been a game-changer. yes...in the city in can get annoying but still useful. in the country-indispensible...
esp on the longer downhills. even in the city when it's beeping every few moment, it comes in handy. the varia alert +
a quick, partial head turn to the (mostly) left or right to let an approaching vehicle know you're aware of their presence is
huuge. my anecdotal sample in the last four months is less aggro and more understanding drivers. may it continue...