This past Tuesday I received an email from Flex service saying they were ready for the part 2 of the PEN update (I had already replaced the heat sink). Boxed it up and with the prepaid UPS label (classy) dropped it of at UPS. Flex received it on Thursday at about 12:30. On Friday I received another email from Austin with the return tracking number saying my 6400 was on the way back to me. Actually the title is not correct in retrospect, it should state "BEYOND AWESOME". Many other manufacturers should take a lesson from Flex service, typically if there is a fault or problem you pay to ship it back, not so with Flex...WELL DONE!