According to Wikipedia (http://en.wikipedia.org/wiki/Photovoltaic_system#Tracking_th...):

"tracking systems can increase viable output by up to 100%...For large systems, the energy gained by using tracking systems outweighs the added complexity (trackers can increase efficiency by 30% or more)"

The new tree design can make 20%-50% more electricity. Wouldn't know till they do some legitimate tests but it seems like the sun trackers fare better.