Originally Posted by
tFUnK
... My main hesitation is that I don't currently ride with a head unit, so the initial investment is a bit steep ...
The Garmin RTL515 will send the information to your phone over Bluetooth. You could get a phone strap mount if you wanted to go for the least expensive option.
I ride on the road and commute with my RTL510 (older version without Bluetooth) and Edge 830, and will never go back to riding on the road without radar.