One question that is puzzling me is: why should you need to reprogram the Flash ROM through the USB interface, if you have an internal Hard Disk ? On my PSR9k I have done it using the Hard Disk (SCSI), storing the OS first on the HD. So, if you have a HD, then it should be possible to store the new OS first on the HD (via the USB). Thus, the speed of the USB interface would not really matter (assuming it is slow). The only thing that would matter is how fast you can load the new OS from the internal HD (given that the loading should not be interrupted, the faster it is the smaller the chances of e.g. a power failure during the loading).

By the way the Tyros cannot read Smart Media cards (or any device for that matter) via the USB. It can only be a USB slave, i.e. some active device like a PC is needed to be connected to the Tyros for transferring data.

Kari