I talked the other day with an employee of my carrier service -Movistar in latinamerica-.
He told me that the long reboot time of blackberry devices turned into a productivity issue for the carriers, when offering support to customers.
He told me that they have to wait between 2-6 minutes for a device to reboot. And sometimes they have to make two or three reboots in one support call when the problem is related with non-standard problems. At the end, one call takes about 10 to 15 minutes, when the time can be shorten in half if blackberry dramatically improves their Operational System loading time.
He also told me that this is one big complain from their users. But there is nothing they can do other than acknowledge the problem and try to be patience when offering support to blackberry users.