A thread with quite a few comments was started 5 days ago discussing the Brad Berman articles (with more details from Berman's plug-in-cars.com write-up):
http://gm-volt.com/forum/showthread.php?17312-Over-530-miles-all-electric-in-less-than-12-hours
http://gm-volt.com/forum/showthread.php?17312-Over-530-miles-all-electric-in-less-than-12-hours