As a Vermont based company, we know snow. Our tracking software optimizes the performance of the Suspension Tracker in snowy climates. For proof, just look at the power production on a 4 kW Solaflect Suspension Tracker in February, 2015, one of the coldest and snowiest Februaries in memory.
Most fixed panels had production close to zero during this snowy month! Look at a fixed ground mount PV system (roof mount PV was similar in February).