>>385674514
Two indeed, 1.0s. 
The Vive tracker is rock-solid.
The Tundra tracks perfectly, until it doesn't, and will then reset and fail to reinitialize itself for a while.

It will complain about back-facing hits while doing this, which combined with how wonky it behaves for the first minute or so after being turned on suggests to me they have IMU problems.

No there are no reflective surfaces.