Hello,
We have been using LM Flash Programmer and the serial bootloader in ROM for production programming and field updates of the LM3S1J11. It works reliably, but we have noticed that it is apparently slower over a USB to serial adapter than through a hardware serial port. This assumes finding a PC whose serial port can even read the signal from a '3232 running at 3.3V, but that's another story. ;)
Specifically, this has been tested with the FTDI FT232RL chip in the form of the US232R USB to serial adapter. These devices have proven to be extremely reliable, and to work better than hardware serial ports for many applications in my experience. We're generally running a fixed baud rate of 115200 bps in both cases. I'm curious if there's something in the bootloader protocol which makes it do a lot of retries due to the slight latency of the USB adapter or something, and if there's any way to speed it up. I have tried playing with the buffering and timing settings in the FTDI driver, and have seen no difference.
Thanks,
---Karl