I use Zwift Run since last year, about 550km logged so far.

Altough I never tried a race, I like it so far, much better than looking at the wall in front of my treadmill.

I use a Garmin foot pod (connected via Ant+, I use a desktop PC to run Zwift at home, with a monitor in front of the treadmill, see pic).

When I'm away from home, in the hotel gyms I use Zwift Run with my iPhone. My foot pod is connected to the phone via a 4iiii HRM.

These setups have been working fine so far, and the pace is sufficiently accurate for me.